Plating apparatus and method

ABSTRACT

An apparatus for plating a conductive film directly on a substrate with a barrier layer on top includes anode rod ( 1 ) placed in tube ( 109 ), and anode rings ( 2 ), and ( 3 ) placed between cylindrical walls ( 107 ) and ( 105 ), ( 103 ) and ( 101 ), respectively. Anodes ( 1 ), ( 2 ), and ( 3 ) are powered by power supplies ( 13 ), ( 12 ), and ( 11 ), respectively. Electrolyte ( 34 ) is pumped by pump ( 33 ) to pass through filter ( 32 ) and reach inlets of liquid mass flow controllers (LMFCs) ( 21 ), ( 22 ), and ( 23 ). Then LMFCs ( 21 ), ( 22 ) and ( 23 ) deliver electrolyte at a set flow rate to sub-plating baths containing anodes ( 3 ), ( 2 ) and ( 1 ), respectively. After flowing through the gap between wafer ( 31 ) and the top of the cylindrical walls ( 101 ), ( 103 ), ( 105 ), ( 107 ) and ( 109 ), electrolyte flows back to tank ( 36 ) through spaces between cylindrical walls ( 100 ) and ( 101 ), ( 103 ) and ( 105 ), and ( 107 ) and ( 109 ), respectively. A pressure leak valve ( 38 ) is placed between the outlet of pump ( 33 ) and electrolyte tank ( 36 ) to leak electrolyte back to tank ( 36 ) when LMFCs ( 21 ), ( 22 ), ( 23 ) are closed. A wafer ( 31 ) held by wafer chuck ( 29 ) is connected to power supplies ( 11 ), ( 12 ) and ( 13 ). A drive mechanism ( 30 ) is used to rotate wafer ( 31 ) around the z axis, and oscillate the wafer in the x, y, and z directions shown. Filter ( 32 ) filters particles larger than 0.1 or 0.2 μm in order to obtain a low particle added plating process.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of earlier filed U.S. ProvisionalApplication Ser. No. 60/074,466, filed on Feb. 12, 1998, and U.S.Provisional Application Ser. No. 60/094,215, filed on Jul. 27, 1998, theentire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a method and apparatus forplating thin films and, more particularly, plating metal films to forminterconnects in semiconductor devices.

2. Description of the Prior Art

As semiconductor device features continue to shrink according to Moore'slaw, interconnect delay is larger than device gate delay for 0.18 μmgeneration devices if aluminum (Al) and SiO2 are still being used. Inorder to reduce the interconnect delay, copper and low k dielectric area possible solution. Copper/low k interconnects provide severaladvantages over traditional Al/SiO2 approaches, including the ability tosignificantly reduce the interconnect delay, while also reducing thenumber of levels of metal required, minimizing power dissipation andreducing manufacturing costs. Copper offers improved reliability in thatits resistance to electromigration is much better than aluminum. Avariety of techniques have been developed to deposit copper, rangingfrom traditional physical vapor deposition (PVD) and chemical vapordeposition (CVD) techniques to new electroplating methods. PVD Cudeposition typically has a cusping problem which results in voids whenfilling small gaps (<0.18 μm) with a large aspect ratio. CVD Cu has highimpurity incorporated inside the film during deposition, which needs ahigh temperature annealing to drive out the impurity in order to obtaina low resistivity Cu film. Only electroplated Cu can provide both lowresistivity and excellent gap filling capability at the same time.Another important factor is the cost; the cost of electroplating toolsis two thirds or half of that of PVD or CVD tools, respectively. Also,low process temperatures (30° to 60° C.) for electroplating Cu areadvantageous with low k dielectrics (polymer, xerogels and aerogels) insucceeding generations of devices.

Electroplated Cu has been used in printed circuit boards, bump platingin chip packages and magnetic heads for many years. In conventionalplating machines, density of plating current flow to the periphery ofwafers is greater than that to the center of wafers. This causes ahigher plating rate at the periphery than at the center of wafers. U.S.Pat. No. 4,304,841 to Grandia et al. discloses a diffuser being putbetween a substrate and an anode in order to obtain uniform platingcurrent flow and electrolyte flow to the substrate. U.S. Pat. No.5,443,707 to Mori discloses manipulating plating current by shrinkingthe size of the anode. U.S. Pat. No. 5,421,987 to Tzanavaras discloses arotating anode with multiple jet nozzles to obtain a uniform and highplating rate. U.S. Pat. No. 5,670,034 to Lowery discloses a transverselyreciprocating anode in front of a rotating wafer to improve platingthickness uniformity. U.S. Pat. No. 5,820,581 to Ang discloses a thiefring powered by a separate power supply to manipulate the platingcurrent distribution across the wafer.

All of these prior art approaches need a Cu seed layer prior to the Cuplating. Usually the Cu seed layer is on the top of a diffusion barrier.This Cu seed layer is deposited either by physical vapor deposition(PVD), or chemical vapor deposition (CVD). As mentioned before, however,PVD Cu typically has a cusping problem, which results in voids whenfilling small gaps (<0.18 μm) with a large aspect ratio with subsequentCu electroplating. CVD Cu has high impurity levels incorporated in thefilm during deposition, requiring a high temperature annealing to driveout the impurities in order to obtain a low resistivity Cu seed layer.As device feature size shrinks this Cu seed layer will become a moreserious problem. Also, deposition of a Cu seed layer adds an additionalprocess, which increases IC fabrication cost.

Another disadvantage of the prior art is that the plating current andelectrolyte flow pattern are manipulated dependently, or only theplating current is manipulated. This limits the process turning window,because the optimum plating current condition does not necessarilysynchronize with optimum electrolyte flow condition for obtainingexcellent gap filling capability, thickness uniformity and electricaluniformity as well as grain size and structure uniformity all at thesame time.

Another disadvantage of the prior art is that plating head or platingsystems are bulky with large foot prints, which causes higher cost ofownership for users.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a novel method and apparatusfor plating a metal film directly on a barrier layer without using aseed layer produced by a process other than plating.

It is a further object of the invention to provide a novel method andapparatus for plating a metal film over a thinner seed layer thanemployed in the prior art.

It is an additional object of the invention to provide a novel methodand apparatus for plating a thin film with a more uniform thicknessacross a wafer.

It is a further object of the invention to provide a novel method andapparatus for plating a conducting film with a more uniform electricalconductivity across a wafer.

It is a further object of the invention to provide a novel method andapparatus for plating a thin film with a more uniform film structure,grain size, texture and orientation.

It is a further object of the invention to provide a novel method andapparatus for plating a thin film with an improved gap fillingcapability across a wafer.

It is a further object of the invention to provide a novel method andapparatus for plating a metal film for interconnects in an integratedcircuit IC chip.

It is a further object of the invention to provide a novel method andapparatus for plating a thin film, with the method and apparatus havingindependent plating current control and electrolyte flow patterncontrol.

It is a further object of the invention to provide a novel method andapparatus for plating a metal thin film for a damascene process.

It is a further object of the invention to provide a novel method andapparatus for plating a metal film with a low impurity level.

It is a further object of the invention to provide a novel method andapparatus for plating copper with a low stress and good adhesion.

It is a further object of the invention to provide a novel method andapparatus for plating a metal film with a low addled particle density.

It is a further object of the invention to provide a novel platingsystem with a small footprint.

It is a further object of the invention to provide a novel platingsystem with a low cost of ownership.

It is a further object of the invention to provide a novel platingsystem which plates a single wafer at a time.

It is a further object of the invention to provide a novel platingsystem with an in-situ film thickness uniformity monitor.

It is a further object of the invention to provide a novel platingsystem with a built-in cleaning system with wafer dry-in and dry-out.

It is a further object of the invention to provide a novel platingsystem with a high wafer throughput.

It is a further object of the invention to provide a novel platingsystem which can handle a wafer size beyond 300 mm.

It is a further object of the invention to provide a novel platingsystem with multiple plating baths and cleaning/drying chambers.

It is a further object of the invention to provide a novel platingsystem with a stacked plating chamber and cleaning/dry chamberstructure.

It is a further object of the invention to provide a novel platingsystem with automation features of the Standard Mechanical Interface(SMIF), the Automated Guided Vehicle (AGV), and the SEMI Equipment(Communication Standard/Generic Equipment Machine (SECS/GEM).

It is a further object of the invention to provide a novel platingsystem meeting Semiconductor Equipment and Materials International(SEMI) and European safety specifications.

It is a further object of the invention to provide a novel platingsystem with high productivity having a large mean time between failures(MTBF), small scheduled down time, and large equipment uptime.

It is a further object of the invention to provide a novel platingsystem controlled by a personal computer with a standard operatingsystem, such as an IBM PC under a Windows NT environment.

It is a further object of the invention to provide a novel platingsystem with a graphical user interface, such as a touch screen.

These and related objects and advantages of the invention may beachieved through use of the novel method and apparatus herein disclosed.A method for plating a film to a desired thickness on a surface of asubstrate in accordance with the invention includes plating the film tothe desired thickness on a first portion of the substrate surface. Thefilm is then plated to the desired thickness on at least a secondportion of the substrate to give a continuous film at the desiredthickness on the substrate. Additional portions of the substrate surfaceadjacent to and contacting the film already plated on one or more of theprevious portions are plated as necessary to give a continuous film overthe entire surface of the substrate.

An apparatus for plating a film on a substrate in accordance with theinvention includes a substrate holder for positioning the substrate forcontact with a plating electrolyte. The apparatus has at least one anodefor supplying plating current to the substrate and at least two flowcontrollers connected to supply electrolyte contacting the substrate. Atleast one control system is coupled to the at least one anode and the atleast two flow controllers to provide electrolyte and plating current incombination to successive portions of the substrate to provide acontinuous, uniform thickness film on the substrate by successiveplating of the film on the portions of the substrate.

In another aspect of the invention, an apparatus for plating a film on asubstrate in accordance with the invention includes a substrate holderfor positioning the substrate for contact with a plating electrolyte.The apparatus has at least two anodes for supplying plating current tothe substrate and at least one flow controller connected to supplyelectrolyte contacting the substrate. At least one control system iscoupled to the at least two anode and the at least one flow controllerto provide electrolyte and plating current in combination to successiveportions of the substrate to provide a continuous, uniform thicknessfilm on the substrate by successive plating of the film on the portionsof the substrate.

In a further aspect of the invention, an apparatus for plating a film ona substrate in accordance with the invention includes a substrate holderfor positioning the substrate for contact with a plating electrolyte.The apparatus has at least one anode for supplying plating current tothe substrate and at least one flow controller connected to supplyelectrolyte contacting the substrate. The at least one flow controllercomprises at least three cylindrical walls, a first of the cylindricalwalls positioned under a center portion of the substrate extendingupward closer to the substrate than a second one of the cylindricalwalls positioned under a second portion of the substrate peripheral tothe center portion. A drive mechanism is coupled to the substrate holderto drive the substrate holder up and down to control one or moreportions of the substrate contacting the electrolyte. At least onecontrol system is coupled to the at least one anode and the at least oneflow controller to provide electrolyte and plating current incombination to successive portions of the substrate to provide acontinuous, uniform thickness film on the substrate by successiveplating of the film on the portions of the substrate.

In yet another aspect of the invention, an apparatus for plating a filmon a substrate in accordance with the invention includes a substrateholder for positioning the substrate for contact with a platingelectrolyte. The apparatus has at least one anode for supplying platingcurrent to the substrate and at least one flow controller connected tosupply electrolyte contacting the substrate. The at least one flowcontroller comprises at least three cylindrical walls movable upwardtoward the substrate and downward away from the substrate, to adjust agap between the substrate and each of the cylindrical walls to controlone or more portions of the substrate contacting the electrolyte. Adrive mechanism is coupled to the substrate holder to drive thesubstrate holder up and down to control one or more portions of thesubstrate contacting the electrolyte. At least one control system iscoupled to the at least one anode and the at least one flow controllerto provide electrolyte and plating current in combination to successiveportions of the substrate to provide a continuous, uniform thicknessfilm on the substrate by successive plating of the film on the portionsof the substrate.

In still another aspect of the invention, an apparatus for plating afilm on a substrate, includes a substrate holder for positioning thesubstrate in a body of electrolyte. At least one movable jet anodesupplies plating current and electrolyte to the substrate. The movablejet anode is movable in a direction parallel to the substrate surface. Aflow controller controls electrolyte flowing through the movable jetanode. At least one control system is coupled to the movable jet anodeand the flow controller to provide electrolyte and plating current incombination to successive portions of the substrate to provide acontinuous, uniform thickness film on the substrate by successiveplating of the film on the portions of the substrate.

In a still further aspect of the invention, an apparatus for plating afilm on a substrate includes a substrate holder for positioning thesubstrate above an electrolyte surface. A first drive mechanism iscoupled to the substrate holder to move the substrate holder toward andaway from the electrolyte surface to control a portion of a surface ofthe substrate contacting the electrolyte. A bath for the electrolyte hasat least one anode mounted in the bath. A second drive mechanism iscoupled to the bath to rotate the bath around a vertical axis to form asubstantially parabolic shape of the electrolyte surface. A controlsystem is coupled to the first and second drive mechanisms and to the atleast one anode to provide electrolyte and plating current incombination to successive portions of the substrate to provide acontinuous, uniform thickness film on the substrate by successiveplating of the film on the portions of the substrate.

In yet another aspect of the invention, an apparatus for plating a filmon a substrate includes a substrate holder for positioning the substrateabove an electrolyte surface. A first drive mechanism is coupled to thesubstrate holder to move the substrate holder toward and away from theelectrolyte surface to control a portion of a surface of the substratecontacting the electrolyte. A second drive mechanism is coupled to thesubstrate holder to rotate the substrate holder around an axis verticalto the surface of the substrate. A third drive mechanism is coupled tothe substrate holder to tilt the substrate holder with respect to theelectrolyte surface. A bath for the electrolyte has at least one anodemounted in the bath. A control system is coupled to the first, secondand third drive mechanisms and to the at least one anode to provideelectrolyte and plating current in combination to successive portions ofthe substrate to provide a continuous, uniform thickness film on thesubstrate by successive plating of the film on the portions of thesubstrate.

In a still further aspect of the invention, a method for plating a filmto a desired thickness on a surface of a substrate includes providing aplurality of stacked plating modules and a substrate transferringmechanism. A substrate substrate is picked from a substrate holder withthe substrate transferring mechanism. The substrate is loaded into afirst one of stacked plating modules with the substrate transferringmechanism. A film is plated on the substrate in the first the one of thestacked plating modules. The substrate is returned to the substrateholder with the substrate transferring mechanism.

In another aspect of the invention, an automated tool for plating a filmon a substrate includes at least two plating baths positioned in astacked relationship, at least one substrate holder and a substratetransferring mechanism. A frame supports the plating baths, thesubstrate holder and the substrate transferring mechanism. A controlsystem is coupled to the substrate transferring mechanism, substrateholder and the plating baths to continuously perform uniform filmdeposition on a plurality of the substrates.

Method 1: Portion of Wafer Surface is Contacted with Electrolyte (StaticAnode)

The above and other objects of the invention are further accomplished bya method for plating a thin film directly on substrate with a barrierlayer on top, comprising: 1) flowing electrolyte on a portion of asubstrate surface with a barrier layer on the top; and 2) turning on DCor pulse power to plate metal film on the same portion area of substrateuntil the film thickness reaches the pre-set value; 3) repeating step 1and 2 for additional portions of the substrate by flowing electrolyte tothe same additional portion of substrate; 4) repeating step 3 until theentire substrate surface is plated with a thin seed layer; 5) flowingelectrolyte to entire area of the substrate; 6) supplying power to applypositive potential to all anodes to plate the thin film until the filmthickness reaches a desired thickness value.

Method 2: Whole Wafer Surface is Contacted by Electrolyte (StaticAnodes)

In a further aspect of the invention there is provided another methodfor plating a thin film directly on a substrate with a barrier layer ontop, comprising: 1) flowing electrolyte on the full surface of thesubstrate; 2) plating the thin film only on a portion of the substratesurface by applying positive potential on an anode close to the sameportion of wafer surface and by applying negative potential on all otheranodes close to the remainder of the substrate surface until the platedfilm thickness on the same portion of the substrate reaches a pre-setvalue; 3) repeating step 2 for an additional portion of the substrate;4) repeating step 3 until the whole area of substrate is plated with athin seed layer; 5) plating a thin film on the whole area of thesubstrate at the same time by applying positive potential to all anodesuntil the thickness of the film on the whole surface of the substratereaches a pre-set thickness value.

Method 3: Whole Wafer Surface is Contacted by Electrolyte at Beginning,and then Portion of Wafer which has been Plated is Moved Out ofElectrolyte

In a farther aspect of the invention there is provided another methodfor plating a thin film directly on a substrate with a barrier layer ontop, comprising: 1) flowing electrolyte on the full surface of asubstrate; 2) plating the thin film only on a portion of the substratesurface by applying positive potential on an anode close to the sameportion of the substrate surface and by applying negative potential onall other anodes close to the remainder of the substrate surface untilthe plated film thickness on the portion of the substrate surfacereaches a pre-set value; 3) move the electrolyte only out of contactwith the all plated portion of the substrate and keep the electrolytestill touching the rest of the non-plated portion of the substrate; 4)repeat steps 2 and 3 for plating the next portion of the substrate; 5)repeat step 4 until the whole area of the substrate is plated with athin seed layer; 6) plate a thin film on the whole substrate at the sametime by applying positive potential to all anodes and flowingelectrolyte on the whole surface of the substrate until the thickness ofthe film on the whole surface of the substrate reaches a pre-setthickness value.

Method 4: A Portion of Substrate is Contacted by Electrolyte atBeginning and then both Plated Portion and the Next Portion of theSubstrate are Contacted by Electrolyte

In a further aspect of the invention there is provided another methodfor plating a thin film directly on a substrate with a barrier layer ontop, comprising: 1) flowing electrolyte on a first portion of thesubstrate surface; and 2) plating the thin film only on the firstportion of the substrate surface by applying positive potential on ananode close to the first portion of the substrate surface until theplated film thickness on the first portion of the substrate reaches apre-set value; 3) moving the electrolyte to contact a second portion ofthe substrate surface and at the same time keep the electrolyte stillcontacting the first portion of the substrate surface; 4) plating thethin film only on the second portion of the substrate surface byapplying positive potential on a anode close to the second portion ofthe substrate surface and applying a negative potential on an anodeclose to the first portion of the substrate surface; 5) repeating step 3and 4 for plating a third portion of the substrate surface; 6) repeatingstep 4 until the whole area of the substrate surface is plated with athin seed layer; 7) plating the thin film on the whole wafer at the sametime by applying positive potential to all anodes and flowingelectrolyte on the full surface of the substrate until the thickness ofthe film on the whole surface of the substrate reaches a pre-setthickness value.

Method 5: Portion of Substrate Surface is Contacted with Electrolyte(Movable Anodes) for Seed Layer Plating Only

In a further aspect of the invention there is provided another methodfor plating a thin film directly on a substrate with a barrier layer ontop, comprising: 1) flowing electrolyte on a portion of the substratesurface with a barrier layer on the top through a movable jet anode; 2)turning on DC or pulse power to plate a metal film on the portion of thesubstrate until the film :thickness reaches a pre-set value; 3)repeating steps 1 and 2 for an additional portion of the substrate bymoving the movable jet anode close to the additional portion of thesubstrate; 4) repeating step 3 until the whole area of the substrate isplated with a thin seed layer.

Method 6: Whole Substrate Surface is Contacted by Electrolyte (MovableAnodes) for Seed Layer Plating Only

In a further aspect of the invention there is provided another methodfor plating a thin film directly on a substrate with a barrier layer ontop, comprising: 1) immersing the full surface of a substrate into anelectrolyte; 2) plating the thin film only on a first portion of thesubstrate surface by applying positive potential on a movable anodeclose to the first portion of the substrate surface; 3) repeating step 2for additional portions of the substrate by moving the movable anodeclose to the additional portions of the substrate; 4) repeating step 3until the whole area of the substrate is plated with a thin seed layer.

Apparatus 1: Multiple Liquid Flow Mass Controllers (LMFCs) and MultiplePower Supplies

In a further aspect of the invention there is provided an apparatus forplating a thin film directly on a substrate with a barrier layer on top,comprising: a substrate holder for holding a substrate above anelectrolyte surface; at least two anodes, with each anode beingseparated by an insulating cylindrical wall; a separate liquid mass flowcontroller for controlling electrolyte flowing through a space betweenthe two cylindrical walls to touch a portion of the substrate; aseparate power supply to create a potential between each anode andcathode or the substrate; the portion of the substrate surface will beplated only when the liquid flow controller and power supplycorresponding to the portion of the substrate is turned on at the sametime.

Apparatus 2: One Common LMFC and Multiple Power Supplies

In a further aspect of the invention there is provided another apparatusfor plating a thin film directly on a substrate with a barrier layer ontop, comprising: a substrate chuck holding the substrate above anelectrolyte surface; a motor driving the substrate holder up or down tocontrol the portion of the surface area contacting the electrolyte; atleast two anodes, with each anode being separated by two insulatingcylindrical walls, the height of the cylindrical walls being reducedalong the outward radial direction of the substrate; one common liquidmass flow controller for controlling electrolyte flowing through spacesbetween each adjacent cylindrical wall to reach the substrate surface;separate power supplies to create potential between each anode andcathode or the substrate; a portion of the substrate surface is platedonly when the anode close to the portion of the substrate is powered topositive potential and the rest of anodes are powered to negativepotential and the portion of the substrate is contacted by theelectrolyte at the same time. After the plating thickness reaches a seedlayer set-value, the substrate is moved up so that the plated portion isout of the electrolyte. This will allow no further plating or etchingwhen other portions of the substrate are plated.

Apparatus 3: Multiple LMFCs and One Common Power Supply

In a further aspect of the invention there is provided another apparatusfor plating a thin film directly on a substrate with a barrier layer ontop, comprising: a substrate holder holding the substrate above anelectrolyte surface; at least two anodes, each anode being separated bytwo insulating cylindrical walls; a separate liquid mass flow controllerfor controlling electrolyte flowing through a space between the twocylindrical walls to touch a portion of the substrate; one common powersupply to create potential between each anode and cathode or thesubstrate; a portion of the substrate surface is plated only when itsliquid mass flow controller and the power supply are turned on at thesame time.

Apparatus 4: One Common LMFC and One Common Power Supply

In a further aspect of the invention there is provided another apparatusfor plating a thin film directly on a substrate with a barrier layer ontop, comprising: a substrate holder holding the substrate above anelectrolyte surface; at least two anodes, each anode being separated bytwo insulating cylindrical walls; the cylindrical walls can be moved upand down to adjust a gap between the substrate and the top of thecylindrical walls, thereby to control electrolyte to contact a portionof the substrate adjacent to the walls, one liquid mass flow controllerfor controlling electrolyte flowing through a space between the twocylindrical walls; one power supply to create potential between allanodes and a cathode or the substrate; a portion of the substratesurface will be plated only when the cylindrical wall below the portionof the substrate surface is moved up so that the electrolyte touches theportion of the substrate and the power supply is turned on at the sametime.

Apparatus 5: Movable Anode with Substrate not Immersed in Electrolyte

In a further aspect of the invention there is provided another apparatusfor plating a thin film directly on a substrate with a barrier layer ontop, comprising: a substrate holder for holding the substrate above anelectrolyte surface; a movable anode jet placed under and close to thesubstrate, the movable anode jet being capable of moving toward thesubstrate surface, thereby the electrolyte from the anode jet can becontrolled to touch any portion of the substrate; one power supply tocreate a potential between the movable anode jet and a cathode or thesubstrate; a portion of substrate surface is plated only when theportion of the surface is contacted by electrolyte ejected from themovable anode jet.

Apparatus 6: Movable Anode with Substrate Immersed in Electrolyte

In a further aspect of the invention there is provided another apparatusfor plating a thin film directly on a substrate with a barrier layer ontop, comprising: a substrate holder for holding a substrate, with thesubstrate being immersed in electrolyte; a movable anode jet adjacent tothe substrate, the movable anode jet being movable toward the substratesurface, whereby the plating current from the anode jet can becontrolled to go to any portion of the substrate; one power supply tocreate potential between the movable anode jet and a cathode or thesubstrate; a portion of substrate surface is plated only when theportion of the substrate is close to the movable anode jet.

Method 7: Plating Metal Film on to Substrate through a Fully AutomationPlating Tool

In a further aspect of the invention there is provided another methodfor plating a thin film onto a substrate through a fully automatedplating tool, comprising: 1) picking up a wafer from a cassette andsending to one of stacked plating baths with a robot; 2) plating metalfilm on the wafer; 3) after finishing the plating, picking up the platedwafer from the stacked plating bath with the robot and transporting itto one of the stacked cleaning/drying chambers; 4) Cleaning the platedwafer; 5) drying the plated wafer; 6) picking up the dried wafer fromthe stacked cleaning/drying chamber with the robot and transporting itto the cassette.

Apparatus 7: Fully Automated Tool for Plating Metal Film on to Substrate

In a further aspect of the invention there is provided a fully automatedtool for plating a metal film onto a substrate, comprising: a robottransporting a wafer; wafer cassettes; multiple stacked plating baths;multiple stacked cleaning/drying baths; an electrolyte tank; and aplumbing box holding a control valve, filter, liquid mass flowingcontroller, and plumbing. The fully automated tool further comprises acomputer and control hardware coupled between the computer and the otherelements of the automated tool, and an operating system control softwarepackage resident on the computer.

Method 8: Plating Thin Layer—Portion of Wafer Surface is Contacted withElectrolyte, and then both Plated Portion and the next Portion of Waferare Contacted by Electrolyte and are Plated by Metal

In a further aspect of the invention there is provided another methodfor plating a thin film directly on a substrate with a barrier layer orthin seed layer on top, comprising: 1) turning on DC or pulse power; 2)making a first portion of the substrate surface contact an electrolyte,so that a metal film is plated on the first portion of the substrate; 3)when the metal film thickness reaches a pre-set value, repeating step 1and 2 for one or more additional portions of the substrate by making theone or more additional portions of the substrate contact theelectrolyte, while continuing to plate the first portion of thesubstrate and any previous of the one or more additional portions of thesubstrate; 4) repeating step 3 until the entire area of the substrate isplated with a thin seed layer.

Method 9: Plating Thin Layer then Thick Layer—Portion of Wafer Surfaceis Contacted with Electrolyte, and then both Plated Portion and the NextPortion of Wafer are Contacted by Electrolyte and are Plated by Metal

In a further aspect of the invention there is provided another methodfor plating a film directly on substrate with a barrier layer or thinseed layer on top, comprising: 1) turning on DC or pulse power, 2)making a first portion of a substrate surface contact an electrolyte, sothat a metal film is plated on the first portion of the substrate; 3)when the metal film thickness reaches a pre-set value, repeating step 1and 2 for one or more additional portions of the substrate by making theone or more additional portions of the substrate contact theelectrolyte, while continuing to plate the first portion of thesubstrate and any previous of the one or more additional portions of thesubstrate; 4) repeating step 3 until all portions of the substrate areplated with a thin seed layer; 5) contacting all of the portions of thesubstrate with the electrolyte; 6) applying positive potential to anodesadjacent to all of the portions of the substrate to plate a film untilthe film thickness reaches a desired thickness value.

Method 10: Plating a Thin Layer—A First Portion of Wafer Surface isContacted by Electrolyte Initially, and then Both the First Portion anda Second Portion of Wafer are Contacted by Electrolyte, but Only theSecond Portion of Wafer is Plated

In a further aspect of the invention there is provided another methodfor plating a film directly on substrate with a barrier layer or thinseed layer on top, comprising: 1) applying a positive potential on afirst anode close to a first portion of the substrate surface; 2)contacting the first portion of the substrate surface with theelectrolyte, so that the film is plated on the first portion of thesubstrate surface; 3) when the film thickness on the first portion ofthe substrate surface reaches a pre-set value, further contacting asecond portion of the substrate surface while maintaining electrolytecontact with the first portion of the substrate surface; 4) plating thefilm only on the second portion of the substrate surface by applyingpositive potential on a second anode close to the second portion of thesubstrate surface and applying a sufficient positive potential on thefirst anode close to the first portion of the substrate surface so thatthe first portion of the substrate surface is not plated but also notdeplated; 5) repeating steps 3 and 4 for plating a third portion of thesubstrate while avoiding deplating of the first and second portions ofthe substrate surface; 6) repeating step 4 for successive areas of thesubstrate surface until whole area of the substrate surface is platedwith a thin seed layer.

Method 11: Plating Thin Layer then Thick Layer—A Portion of Wafer isContacted by Electrolyte at Beginning and then both Plated Portion andthe Next Portion of Wafer are Contacted by Electrolyte, and Only theNext Portion of Wafer is Plated

In a further aspect of the invention there is provided another methodfor plating a film directly on substrate with a barrier layer or thinseed layer on top, comprising: 1) contacting a first portion of asubstrate area with an electrolyte; and 2) plating thin film only on thefirst portion of the substrate surface by applying positive potential ona first anode close to the same portion of wafer surface until a platedfilm thickness on the first portion of the substrate surface reaches apre-set value; 3) further contacting a second portion of the substratesurface while maintaining electrolyte contact with the first portion ofthe substrate surface; 4) plating the film only on the second portion ofthe substrate surface by applying positive potential on a second anodeclose to the second portion of the substrate surface and applying asufficient positive potential on the first anode close to the firstportion of the substrate surface so that the first portion of thesubstrate surface is not plated but also not deplated; 5) repeatingsteps 3 and 4 for plating a third portion of the substrate whileavoiding deplating of the first and second portions of the substratesurface; 6) repeating step 4 until whole area of the substrate surfaceis plated with a thin seed layer; 7) plating a further metal film on thewhole wafer at the same time by applying positive potential to allanodes and contacting the whole area of the substrate surface until athickness of the further film on the whole substrate surface reaches adesired thickness value.

Apparatus 8: Rotating Plating Bath to Form Parabolic Shape ofElectrolyte (Single-anode)

In a further aspect of the invention there is provided another apparatusfor plating a film directly on a substrate with a barrier layer or thinseed layer on top, comprising: a substrate chuck holding the substrateabove an electrolyte surface; a motor driving the substrate holder up ordown to control the portion of the surface area contacting theelectrolyte; a bath with an anode immersed; a liquid mass flowcontroller for controlling electrolyte flowing to contact the substrate;a power source to create potential between the anode and a cathode orsubstrate; another motor driving the plating bath to rotate around itscentral axis at such a speed that a surface of the electrolyte surfaceforms a parabolic shape; a portion of the substrate surface is platedonly when the liquid mass flow controller and the power supply areturned on at the same time. After a plating thickness reaches a seedlayer predetermined value, the substrate is moved down so that the nextportion of the substrate is contacting the electrolyte and is plated.

Apparatus 9: Rotating Plating Bath to Form Parabolic Shape ofElectrolyte (Multi-anodes)

In a further aspect of the invention there is provided another apparatusfor plating a film directly on a substrate with a barrier layer or thinseed layer on top, comprising: a substrate chuck holding the substrateabove an electrolyte surface; a motor driving the substrate holder up ordown to control the portion of the surface area contacting theelectrolyte; at least two anodes, each anode being separated by twoinsulating cylindrical walls; a separate liquid mass flow controller forcontrolling electrolyte flowing through a space between the twocylindrical walls to contact a portion of the substrate; separate powersupplies to create potential between each anode and cathode or thesubstrate; another motor driving the plating bath to rotate around itscentral axis at such a speed that a surface of the electrolyte surfaceforms a parabolic shape; a portion of the substrate surface will beplated only when the anode close to that portion of the substrate ispowered to positive as well as that portion of the substrate surface iscontacted by electrolyte at the same time. After a plating thicknessreaches a predetermined value, the substrate is moved down so that thenext portion of the substrate is contacting the electrolyte and isplated.

Apparatus 10: Tilting Wafer Holder Around y-axis or x-axis(Single-anode)

In a further aspect of the invention there is provided another apparatusfor plating a film directly on a substrate with a barrier layer or thinseed layer on top, comprising: a substrate chuck holding the substrateabove an electrolyte surface, the substrate holder being rotatablearound a z-axis, and also tiltable around a y-axis or an x-axis; ananode; a liquid mass flow controller for controlling the electrolyte tocontact the substrate; a power source to create potential between theanode and a cathode or substrate; a peripheral portion of the substratesurface will be plated only when the substrate chuck is tilted aroundthe y-axis or x-axis and is rotated around the z-axis so that theperipheral portion of the substrate is contacted by electrolyte, and theliquid mass flow controller and power source are turned on at the sametime.

Apparatus 11: Tilting Rotation Axis of Wafer Holder (Multi-anodes)

In a further aspect of the invention there is provided another apparatusfor plating a film directly on a substrate with a barrier layer or thinseed layer on top, comprising: a substrate chuck holding the substrateabove an electrolyte surface, the substrate holder being rotatablearound a z-axis, and also tiltable around a y-axis or an x-axis; atleast two anodes, each anode being separated by two insulatingcylindrical walls; a separate liquid mass flow controller forcontrolling electrolyte flowing through a space between the twocylindrical walls to contact a portion of the substrate; separate powersupplies to create potential between each anode and cathode or thesubstrate; a peripheral portion of the substrate surface will be platedonly when the substrate chuck is tilted around the y-axis or x-axis andis rotated around the z-axis so that the peripheral portion of thesubstrate is contacted by electrolyte, and the liquid mass flowcontrollers and power source are turned on at the same time.

Apparatus 12: Rotating Plating Bath to Form Parabolic Shape ofElectrolyte and Tilting Wafer Holder Around y-axis or x-axis(Single-anode)

In a further aspect of the invention there is provided another apparatusfor plating a film directly on a substrate with a barrier layer or thinseed layer on top, comprising: a substrate chuck holding the substrateabove an electrolyte surface; a motor driving the substrate holder up ordown to control the portion of the surface area contacting theelectrolyte; the substrate holder being rotatable around a z-axis, andalso tiltable around a y-axis or an x-axis; an anode; a liquid mass flowcontroller for controlling the electrolyte to contact the substrate; apower source to create potential between the anode and a cathode orsubstrate; another motor driving the plating bath to rotate around itscentral axis at such a speed that a surface of the electrolyte surfaceforms a parabolic shape; a peripheral portion of the substrate surfacewill be plated only when the substrate chuck is tilted around the y-axisor x-axis and is rotated around the z-axis so that the peripheralportion of the substrate is contacted by electrolyte, and the liquidmass flow controller and power source are turned on at the same time.

Apparatus 13: Rotating Plating Bath to Form Parabolic Shape ofElectrolyte and Tilting Wafer Holder Around y-axis or x-axis(Multi-anodes)

In a further aspect of the invention there is provided another apparatusfor plating a film directly on a substrate with a barrier layer or thinseed layer on top, comprising: a substrate chuck holding the substrateabove an electrolyte surface; a motor driving the substrate holder up ordown to control the portion of the surface area contacting theelectrolyte; the substrate holder being rotatable around a z-axis, andalso tiltable around a y-axis or an x-axis; at least two anodes, eachanode being separated by two insulating cylindrical walls, thecylindrical walls being closer to the substrate at its center than atits edge; a separate liquid mass flow controller for controllingelectrolyte flowing through a space between the two cylindrical walls tocontact a portion of the substrate; separate power supplies to createpotential between each anode and cathode or the substrate; another motordriving the plating bath to rotate around its central axis at such aspeed that a surface of the electrolyte surface forms a parabolic shape;a portion of the substrate surface will be plated only when the anodeclose to that portion of the substrate is powered to positive as well asthat portion of the substrate surface being contacted by electrolyte atthe same time. After a plating thickness reaches a predetermined value,the substrate is moved down so that the next portion of the substrate iscontacted by the electrolyte and is plated.

The central idea of this invention for plating a metal film withoutusing a seed layer produced by a process other than plating is to plateone portion of wafer a time to reduce current load to a barrier layer,since the barrier layer typically has 100 times higher resistivity thana copper metal film. For details, please see following theoreticalanalysis.

The attainment of the foregoing and related objects, advantages andfeatures of the invention should be more readily apparent to thoseskilled in the art, after review of the following more detaileddescription of the invention, taken together with the drawings, inwhich:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a portion of a prior art plating apparatus, useful forunderstanding the invention.

FIG. 1B is a plan view of a substrate shown in FIG. 1.

FIG. 2 is a corresponding plan view of a substrate during plating inaccordance with the invention.

FIG. 3A is a plan view of a portion of a plating apparatus in accordancewith the invention

FIG. 3B is a view, partly in cross section, taken along the line 3B—3Bin FIG. 3A, and partly in block diagram form, of a plating apparatus inaccordance with the invention.

FIG. 4A is a plan view of a substrate ready for plating in accordancewith the invention.

FIG. 4B is a cross section view, taken along the line 4A—4A of thesubstrate in FIG. 4A.

FIG. 5 is a set of waveform diagrams, useful for understanding operationof the FIGS. 3A-3B embodiment of the invention.

FIGS. 6A and 6B are partial cross section views of plated substrates,useful for further understanding of the invention.

FIGS. 7 and 8 are additional sets of waveform diagrams, useful for afurther understanding operation of the FIGS. 3A-3B embodiment of theinvention.

FIGS. 9A-9D are plan views of portions of alternative embodiments ofplating apparatuses in accordance with the invention.

FIG. 10 is a plot of waveforms obtained in operation of apparatus inaccordance with the invention.

FIG. 11 is a flow diagram for a process in accordance with theinvention.

FIG. 12 is a set of waveform diagrams for an another embodiment of aprocess in accordance with the invention.

FIG. 13A is a plan view of a portion of a second embodiment of a platingapparatus in accordance with the invention.

FIG. 13B is a view, partly in cross section, taken along the line13B—13B in FIG. 13A, and partly in block diagram form, of the secondembodiment of a plating apparatus in accordance with the invention.

FIG. 14A is a plan view of a portion of a third embodiment of a platingapparatus in accordance with the invention.

FIG. 14B is a view, partly in cross section, taken along the line14B—14B in FIG. 14A, and partly in block diagram form, of the thirdembodiment of a plating apparatus in accordance with the invention.

FIG. 15A is a plan view of a portion of a fourth embodiment of a platingapparatus in accordance with the invention.

FIG. 15B is a view, partly in cross section, taken along the line15B—15B in FIG. 15A, and partly in block diagram form, of the fourthembodiment of a plating apparatus in accordance with the invention.

FIG. 16A is a plan view of a portion of a fifth embodiment of a platingapparatus in accordance with the invention.

FIG. 16B is a view, partly in cross section, taken along the line16B—16B in FIG. 16A, and partly in block diagram form, of the fifthembodiment of a plating apparatus in accordance with the invention.

FIG. 17 is a cross section view of a portion of a fifth embodiment of aplating apparatus in accordance with the invention.

FIG. 18A is a plan view of a portion of a sixth embodiment of a platingapparatus in accordance with the invention.

FIG. 18B is a view, partly in cross section, taken along the line18B—18B in FIG. 18A, and partly in block diagram form, of the sixthembodiment of a plating apparatus in accordance with the invention.

FIG. 19A is a plan view of a portion of a seventh embodiment of aplating apparatus in accordance with the invention.

FIG. 19B is a view, partly in cross section, taken along the line19B—19B in FIG. 19A, and partly in block diagram form, of the seventhembodiment of a plating apparatus in accordance with the invention.

FIGS. 20A and 20B are views, partly in cross section and partly in blockdiagram form, of an eighth embodiment of a plating apparatus inaccordance with the invention.

FIGS. 21A and 21B are views, partly in cross section and partly in blockdiagram form, of a ninth embodiment of a plating apparatus in accordancewith the invention.

FIG. 22A is a plan view of a portion of a tenth embodiment of a platingapparatus in accordance with the invention.

FIG. 22B is a view, partly in cross section, taken along the line22B—22B in FIG. 22A, and partly in block diagram form, of the tenthembodiment of a plating apparatus in accordance with the invention.

FIGS. 23A and 23B are plan views of a portion of eleventh and twelfthembodiments of plating apparatus in accordance with the invention.

FIG. 24A is a plan view of a portion of a thirteenth embodiment of aplating apparatus in accordance with the invention.

FIG. 24B is a view, partly in cross section, taken along the line24B—24B in FIG. 24A, and partly in block diagram form, of the thirteenthembodiment of a plating apparatus in accordance with the invention.

FIGS. 25A-25C are plan views of a portion of fourteenth, fifteenth andsixteenth embodiments of plating apparatus in accordance with theinvention.

FIG. 26A is a plan view of a portion of a seventeenth embodiment of aplating apparatus in accordance with the invention.

FIG. 26B is a view, partly in cross section, taken along the line26B—26B in FIG. 26A, and partly in block diagram form, of theseventeenth embodiment of a plating apparatus in accordance with theinvention.

FIGS. 27 and 28 are plan views of a portion of eighteenth and nineteenthembodiments of plating apparatus in accordance with the invention.

FIGS. 29A-29C are plan views of a portion of twentieth, twenty first andtwenty second embodiments of plating apparatus in accordance with theinvention.

FIG. 30A is a plan view of a portion of a twenty third embodiment of aplating apparatus in accordance with the invention.

FIG. 30B is a view, partly in cross section, taken along the line30B—30B in FIG. 30A, and partly in block diagram form, of the twentythird embodiment of a plating apparatus in accordance with theinvention.

FIG. 31A is a plan view of a portion of a twenty fourth embodiment of aplating apparatus in accordance with the invention.

FIG. 31B is a view, partly in cross section, taken along the line31B—31B in FIG. 31A, and partly in block diagram form, of the twentyfourth embodiment of a plating apparatus in accordance with theinvention.

FIG. 32A is a plan view of a portion of a twenty fifth embodiment of aplating apparatus in accordance with the invention.

FIG. 32B is a view, partly in cross section, taken along the line32B—32B in FIG. 32A, and partly in block diagram form, of the twentyfifth embodiment of a plating apparatus in accordance with theinvention.

FIG. 33A is a plan view of a portion of a twenty sixth embodiment of aplating apparatus in accordance with the invention.

FIG. 33B is a view, partly in cross section, taken along the line33B—33B in FIG. 33A, and partly in block diagram form, of the twentysixth embodiment of a plating apparatus in accordance with theinvention.

FIGS. 34A-34D are cross section views of a portion of twenth sevenththrough thirtieth embodiments of plating apparatus in accordance withthe invention.

FIG. 35 shows a substrate during plating with a process in accordancewith the invention.

FIGS. 36A-36D are plan views of thirty first through thirty fourthembodiments of plating apparatus in accordance with the invention.

FIGS. 37A and 37B are cross section views of a portion of thirty fifthand thirty sixth embodiments of plating apparatus in accordance with theinvention.

FIG. 38A is a plan view of a portion of a thirty seventh embodiment of aplating apparatus in accordance with the invention.

FIG. 38B is a view, partly in cross section, taken along the line38B—38B in FIG. 38A, and partly in block diagram form, of the thirtyseventh embodiment of a plating apparatus in accordance with theinvention.

FIG. 39 is a set of waveform diagrams useful for understanding operationof the plating apparatus in FIGS. 38A and 38B.

FIG. 40A is a plan view of a portion of a thirty eighth embodiment of aplating apparatus in accordance with the invention.

FIG. 40B is a view, partly in cross section, taken along the line40B—40B in FIG. 40A, and partly in block diagram form, of the thirtyeighth embodiment of a plating apparatus in accordance with theinvention.

FIG. 41A is a plan view of a portion of a thirty ninth embodiment of aplating apparatus in accordance with the invention.

FIG. 41B is a view, partly in cross section, taken along the line41B—41B in FIG. 41A, and partly in block diagram form, of the thirtyninth embodiment of a plating apparatus in accordance with theinvention.

FIG. 42A is a plan view of a portion of a fortieth embodiment of aplating apparatus in accordance with the invention.

FIG. 42B is a view, partly in cross section, taken along the line42B—42B in FIG. 42A, and partly in block diagram form, of the fortiethembodiment of a plating apparatus in accordance with the invention.

FIGS. 43 and 44 are sets of waveform diagrams useful for understandingoperation of the embodiment of FIGS. 42A and 42B.

FIG. 45A is a plan view of a portion of a forty first embodiment of aplating apparatus in accordance with the invention.

FIG. 45B is a view, partly in cross section, taken along the line45B—45B in FIG. 45A, and partly in block diagram form, of the fortyfirst embodiment of a plating apparatus in accordance with theinvention.

FIG. 46A is a plan view of a portion of a forty second embodiment of aplating apparatus in accordance with the invention.

FIG. 46B is a view, partly in cross section, taken along the line46B—46B in FIG. 46A, and partly in block diagram form, of the fortysecond embodiment of a plating apparatus in accordance with theinvention.

FIG. 47A is a plan view of a portion of a forty third embodiment of aplating apparatus in accordance with the invention.

FIG. 47B is a view, partly in cross section, taken along the line47B—47B in FIG. 47A, and partly in block diagram form, of the fortythird embodiment of a plating apparatus in accordance with theinvention.

FIG. 48A is a plan view of a portion of a forty fourth embodiment of aplating apparatus in accordance with the invention.

FIG. 48B is a view, partly in cross section, taken along the line48B—48B in FIG. 48A, and partly in block diagram form, of the fortyfourth embodiment of a plating apparatus in accordance with theinvention.

FIG. 49A is a plan view of a portion of a forty fifth embodiment of aplating apparatus in accordance with the invention.

FIG. 49B is a view, partly in cross section, taken along the line49B—49B in FIG. 49A, and partly in block diagram form, of the fortyfifth embodiment of a plating apparatus in accordance with theinvention.

FIG. 50 is a view, partly in cross section and partly in block diagramform, of a forty sixth embodiment of a plating apparatus in accordancewith the invention.

FIG. 51 is a view, partly in cross section and partly in block diagramform, of a forty seventh embodiment of a plating apparatus in accordancewith the invention.

FIGS. 52A-52C are schematic top, cross section and side views of a firstembodiment of a plating system in accordance with the invention.

FIG. 53 is a flaw diagram of operation of a portion of software forcontrolling the plating system of FIG. 52.

FIGS. 54A-54C are schematic top, cross section and side views of asecond embodiment of a plating system in accordance with the invention.

FIGS. 55 and 56 are schematic top views of third and fourth embodimentsof plating systems in accordance with the invention.

FIGS. 57A-57C are schematic top, cross section and side views of aplating system in accordance with the invention.

FIG. 58A is a plan view of a portion of a forty eighth embodiment of aplating apparatus in accordance with the invention.

FIG. 58B is a view, partly in cross section, taken along the line58B—58B in FIG. 58A, and partly in block diagram form, of the fortyeighth embodiment of a plating apparatus in accordance with theinvention.

FIG. 59 is a set of waveform diagrams showing power supply on/offsequences in use of the FIGS. 58A-58B embodiment during plating.

FIG. 60A is a plan view of a portion of a forty ninth embodiment of aplating apparatus in accordance with the invention.

FIG. 60B is a cross section view, partly taken along the line 60B—60B inFIG. 60A, of the forty ninth embodiment of a plating apparatus inaccordance with the invention.

FIG. 61 is a partly cross section and partly schematic view of afiftieth embodiment of a plating apparatus in accordance with theinvention.

FIGS. 62-71 are schematic views of fifty first through sixtiethembodiments of plating apparatuses in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to the drawings, more particularly to FIGS. 1A-1B, there isshown a portion of a prior art plating apparatus, useful forunderstanding the present invention.

Theoretical Calculation of Potential Difference Between Center and Edgeof Wafer During Conventional Plating

FIGS. 1A shows a cross section view of a conventional fountain typeplating tool and a semiconductor wafer 31 with a thin barrier layer 400.The following theoretical calculation is for determining the potentialdifference between the center and the periphery of the wafer duringnormal plating. Assuming plating current density on the whole wafersurface is the same, the potential difference can be calculated by thefollowing formula: $\begin{matrix}{V = {\left( \frac{I_{0}\rho_{s}}{4\pi \quad r_{0}^{2}} \right)\left( {r^{2} - r_{0}^{2}} \right)}} & (1)\end{matrix}$

where: r is the radius (cm:), r₀ is the radius of a wafer (cm), I₀ isthe total plating current flow to the wafer (Amp.), ρ_(s) is the sheetresistance of barrier layer (Ω/square).

Assuming the atomic radius=3 Å, then we can calculate that the surfacedensity is 1E15 atom/cm². The density of current flowing to the wafercan be expressed as: $\begin{matrix}{I_{D} = {\left( \frac{2 \times 1{E15}}{60} \right)\left( \frac{q\quad {P.R.}}{D_{atom}} \right)}} & (2)\end{matrix}$

where, I_(D) is the plating current density (A/cm²), q is the charge ofan electron (C), P.R. is the plating rate (Å/min), D_(atom) is thediameter of an atom. Substitute P.R.=2000 Å/min, q=1.82E−19° C., and=3 Åinto eq.(2): $\begin{matrix}{I_{D} = {{\left( \frac{2 \times 1{E15}}{60} \right)\left( \frac{1.62\quad E\text{-}19 \times 2000.}{3} \right)} = {3.6\quad E\text{-}3\quad {A/{cm}^{2}}}}} & (3)\end{matrix}$

Total current flowing to a 200 mm wafer is

I₀=πr₀ ²I_(D)=3.14×100×3.6E−3=1.13 Amp.  (4)

Sheet resistance depends on thickness of film, and the method ofdepositing the film. Sheet resistance at thickness of 200 Å anddeposited by a normal PVD or CVD method is in a range of 100 to 300Ω/square. Substituting above I ₀=1.13 Amp., ρ_(s)=100 to 300 Ω/square,and r=0, r₀=10 cm into eq.(1), the potential difference between thecenter and the periphery (edge) of the wafer is:

V=8.96 to 26.9 Volt.  (5)

The normal plating voltage in acid Cu plating is in a range of 2 to 4Volts. It is clear that such a potential difference will make itimpossible to plate directly onto barrier layer by a conventionalplating tool. Even though metal still can be plated on the center of thewafer by using over voltage, a substantial quantity of H⁺ ions will comeout together with metal ions at the periphery of the wafer, which makesa poor quality of metal film. For the semiconductor interconnectapplication, plated copper film will have a very large resistivity, andpoor morphology.

Theoretical Calculation of Potential Difference Between Outside andInside of Plating Area During Plating of the Invention

As shown in FIG. 2, the invention only plates a portion of wafer at onetime. The potential difference between the position at radius r₂ and theposition at radius r₁ can be expressed as: $\begin{matrix}\begin{matrix}{V_{21} = {{\int{v}} = {{\int{I{R}}} = {\int{{I_{D}\left( {{\pi \quad r_{2}^{2}} - {\pi \quad r_{1}^{2}}} \right)}\left( {{\rho_{s}/2}\pi \quad r} \right){r}}}}}} \\{= {\left( {I_{D}{\rho_{s}/2}} \right)\left\lbrack {\left( {{0.5\quad r_{2}^{2}} - {r_{1}^{2}\ln \quad r_{2}}} \right) - \left( {{0.5\quad r_{1}^{2}} - {r_{1}^{2}\quad \ln \quad r_{1}}} \right)} \right\rbrack}}\end{matrix} & (6)\end{matrix}$

The worst case is on the periphery of the wafer. Substitute r₁=9 cm,r₂=10 cm, I_(D)=3.6E−3 Amp.(corresponding to P.R.=2000 Å/min), ρ_(s)=100to 300 Ω/square into eq.(6):

V₂₁=0.173 to 0.522 Volts  (7)

Hydrogen overvoltage is about 0.83 V. It is clear that no hydrogen comesout during plating in accordance with the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

In describing the variety of embodiments of the invention, correspondingparts in different figures are designated with the same reference numberin order to minimize repetitive description.

1. Multiple Power Supplies and Multiple LMFCs

FIGS. 3A-3B are schematic views of one embodiment of the apparatus forplating a conductive film directly on a substrate with a barrier layeron top in accordance with the present invention. The plating bathincludes anode rod 1 placed in tube 109, and anode rings 2, and 3 placedbetween cylindrical walls 107 and 105, 103 and 101, respectively. Anodes1, 2, and 3 are powered by power supplies 13, 12, and 11, respectively.Electrolyte 34 is pumped by pump 33 to pass through filter 32 and reachinlets of liquid mass flow controllers (LMFCs) 21, 22, and 23.

Then LMFCs 21, 22 and 23 deliver electrolyte at a set flow rate tosub-plating baths containing anodes 3, 2 and 1, respectively. Afterflowing through the gap between wafer 31 and the top of the cylindricalwalls 101, 103, 105, 107 and 109, electrolyte flows back to tank 36through spaces between cylindrical walls 100 and 101, 103 and 105, and107 and 109, respectively. A pressure leak valve 38 is placed betweenthe outlet of pump 33 and electrolyte tank 36 to leak electrolyte backto tank 36 when LMFCs 21, 22, 23 are closed. Bath temperature iscontrolled by heater 42, temperature sensor 40, and heater controller44. A wafer 31 held by wafer chuck 29 is connected to power supplies 11,12 and 13. A drive mechanism 30 is used to rotate wafer 31 around the zaxis, and oscillate the wafer in the x, y, and z directions shown. TheLMFCs are anti-acid or anti corrosion, and contamination free type massflow controllers of a type known in the art. Filter 32 filters particleslarger than 0.1 or 0.2 μm in order to obtain a low particle addedplating process. Pump 33 should be an anti-acid or anticorrosion, andcontamination free pump. Cylindrical walls 100, 1001, 103, 105, 107 and109 are made of electrically insulating, anti-acid or anti-corrosion,and non-acid dissolved, metal free materials, such astetrafluoroethylene, polyvinyl chloride (PVC), polyvinylidene fluoride(PVDF), polypropylene, or the like.

FIGS. 4A-4B show the wafer 31 with barrier layer 203 on top. The barrierlayer 203 is used to block diffusion of the plated metal into thesilicon wafer. Typically, titanium nitride or tantalum nitride are used.In order to reduce the contact resistance between the cathode lead wireand the barrier layer, a metal film 201 is deposited by PVD or CVD onthe periphery of wafer 31. The thickness of metal film 201 is in a rangeof 500 Å to 2000 Å. The material of film 201 is preferably the same asthat plated later. For example, Cu is preferably chosen as material offilm 201 for plating a Cu film.

1A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on LMFC 21 only, so that electrolyte only touches a portionof wafer 31 above anode 3.

Step 2: After the flow of electrolyte is stabilized, turn on powersupply 11. Positive metal ion will be plated onto portion area of wafer31 above anode 3.

Step 3: When the thickness of the metal conductive film reaches theset-value or thickness, turn off power supply 11 and turn off LMFC 21.

Step 4: Repeat step 1 to 3 for anode 2, using LMFC 22 and power supply12.

Step 5: Repeat step 4 for anode 1, using LMFC 23 and power supply 13.

During the above plating process, the power supplies can be operated inDC mode, pulse mode, or DC pulse mixed mode. In DC mode, the powersupplies can be operated in a constant current mode, or a constantvoltage mode, or a combination of the constant current mode and constantvoltage mode. The combination of the constant current mode and constantvoltage mode means that the power supply can be switched from one modeto the other mode during the plating process. FIG. 5 shows each poweron/off sequence during a representative seed layer plating. T_(p) iscalled plating time, i.e. positive pulse on time during one cycle; T_(e)is called etching time, i.e. negative pulse on time during one cycle.T_(e)/T_(p) is called the etching plating ratio. It is generally in therange of 0 to 1. As shown in FIG. 6A and 6B, a large ratio ofT_(e)/T_(p) means better gap filling or less cusping, but a lowerplating rate. A small ratio of T_(e)/T_(p) means a higher plating rate,but poor gap filling or more cusping.

1B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 1A.

Step 6: Turn on LMFCs 21, 22, and 23. In principle, the flow rate ofelectrolyte from each LMFC is set as proportional to wafer area coveredby the corresponding anode.

Step 7: After all flow is stabilized, turn on power supplies 11, 12, and13. In principle, the current of each power supply is also set asproportional to the wafer area covered by corresponding anode.

Step 8: Turn off power supplies 11, 12, and 13 at the same time whenplating current is used as thickness uniformity tuning variable.Alternatively, the power supplies can be turned off at different timesfor adjusting plating film thickness uniformity.

FIG. 7 shows a representative sequence for plating metal film on thepre-plated metal seed layer. As mentioned above, total plating time T₃,T₂, and T₁ can be the same when using the plating current as a variableto tune thickness uniformity within wafer, or can be different whenusing plating time to tuning the thickness uniformity within a wafer.

The number of anodes can be any number larger than 1. The moreelectrodes, the better film uniformity can be expected. Considering atrade off between the performance and cost, the number of the anodes istypically 7 to 20 for plating a 200 mm wafer, and 10 to 30 for plating a300 mm wafer.

As shown in FIG. 8, instead of using the bipolar pulse wave form (a), amodified sine-wave pulse wave form (b), a unipolar pulse wave form (c),a pulse reverse wave form (d), a pulse-on-pulse wave form (e), or aduplex pulse wave form (f) can be used.

In a seed layer plating process, a sequence of anode 3, then anode 2,and then anode 1 is usually preferred, but the plating sequence can alsobe as follows:

1) anode 1, then anode 2, and then anode 3;

2) anode 2, then anode 1, and then anode 3;

3) anode 2, then anode 3, and then anode 1;

4) anode 3, then anode 1, and then anode 2; or

5) anode 1, then anode 3, and then anode 2

FIGS. 9A-9D show schematic cross section views of other embodiments ofanode and wall shapes. It can be seen that the wafer area above thespace between electrode 103 and 105 receives less plating current thanthe wafer area above anode 3 does in the case of FIG. 3. This causesthickness variation across the wafer if wafer is only rotated duringplating process. In order to plate a better uniformity of film withoutoscillating wafer in the x and y directions, the shape of the anodes andwalls can be, for example, a triangle, square, rectangle, pentagon,polygon, or ellipse. In these ways, the plating current distribution canbe averaged out across the wafer.

FIG. 10 shows a mechanism to verify if the seed layer becomes acontinuous film across the whole wafer. Since the resistivity of abarrier layer (Ti/TiN or Ta/TaN) is about 50 to 100 times that ofmetallic copper, the potential difference between an edge and the centerbefore plating a seed layer is much higher than that after plating acontinuous copper seed layer. This resistance can be calculated bymeasuring the output voltage and current of power supplies 11, 12 and 13as shown in FIG. 10. When the seed layer becomes a continuous film, theloading resistance reduces significantly. In this way, it also can bedetermined which area is not covered by a continuous film. For instance:

Logic Table 1

1) if V₁₁, V₁₂ are small, and V₁₃ is large, then the film on the waferarea above anode 1 is not continuous;

2) if V₁₁ is small, and V₁₂ and V₁₃ are large, then at least the film onthe wafer area above anode 2 is not continuous;

further under condition (2),

if V₁₂ and V₁₃ are close to each other, then the film on the wafer areaabove anode 1 is continuous;

if V₁₂ and V₁₃ are significantly different, then the film on the waferarea above anode 1 is not continuous;

3) if V₁₁, V₁₂ and V₁₃ are large, then at least the film on the waferarea above anode 3 is not continuous;

further under condition (3)

if V₁₂ and V₁₃ are significantly different, then the film on the waferareas above anode 2 and anode 1 are not continuous;

If V₁₁ and V₁₂ are significantly different, and V₁₂ and V₁₃ are close toeach other, then the film on the wafer area above anode 2 is notcontinuous, but the film on the wafer area above area 1 is continuous;

If V₁₁ and V₁₂ are close to each other, and V₁₂ and V₁₃ aresignificantly different, then the film on the wafer area anode 2 iscontinuous, and the film on the wafer area above anode 1 is notcontinuous.

If V₁₂ and V₁₃ are close to V₁₁, then the film on the wafer areas aboveanode 1 and 2 are continuous.

Through a logic check as shown in FIG. 11, it can be figured out wherethe seed layer is continuous. Then further seed layer plating can beperformed.

FIG. 12 shows a process sequence for plating a seed layer with the wholearea wafer immersed in electrolyte employing the embodiment of FIGS.3A-3B. In the first half cycle, the wafer area above anode 3 is inplating mode, and wafer areas above anode 2 and 1 are in etching mode.In the second half cycle, the wafer area above anode 3 is in etchingmode, and wafer areas above anodes 2 and 1 are in plating mode. In thisway, part of the plating current is cancelled by etching current, andtherefore total current flow to the periphery of the wafer issignificantly reduced. Instead of using a bipolar pulse wave form, otherpulse wave forms as shown in FIG. 7 also can be used.

FIGS. 13A-13B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 13A-13B is similar to that of FIGS. 3A-3B except that LMFCs 21,22 and 23 are replaced by valves 51, 52, 53 and LMFC 55. Valves 51, 52and 53 are on/off valves. The flow rate setting of LMFC 55 is determinedby the status of each valve as follows:

Flow rate setting of LMFC 55=F.R. 3×f(valve 51)+

F.R. 2×f(valve 52)+

F.R. 1×f(valve 53)

where: F.R. 1 is the flow rate setting for anode 1, F.R. 2 the flow ratesetting for anode 2, and F.R. 3 is the flow rate setting for anode 3,and f (valve #) is the valve status function defined as follows:

f(valve #)=1, when valve # is turned on;

0, when valve # is turned off.

FIGS. 14A-14B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 14A-14B is similar to that of FIGS. 3A-3B except that LMFCs 21,22 and 23 are replaced by on/off valves 51, 52, 53 and three pumps 33.Electrolyte flowing to each anode is controlled independently by onepump 33 and one on/off valve.

FIGS. 15A-15B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 15A-5B is similar to that of FIGS. 3A-3B except that additionalanodes 5 and 4 are added between cylindrical walls 109 and 107, andbetween cylindrical walls 103 and 105, respectively, anode 3 andcylindrical wall 101 are taken out, and on/off valves 81, 82, 83, 84 areinserted between the outlet of LMFCs 21, 22, 23, 24 and tank 36.

2A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on LMFC 21 and valves 82, 83, and 84; turn off LMFCS 22,23, 24 and valve 81, so that electrolyte only touches the portion of thewafer above anode 4, and then flows back to tank 36 through return pathspaces between cylindrical walls 100 and 103, through valves 82, 83, and84.

Step 2: After flow of electrolyte stabilized, turn on power supply 11.Positive metal ions will be plated onto the portion of wafer 31 aboveanode 4.

Step 3: When the thickness of the conductive film reaches thepredetermined set-value or thickness, turn off power supply 11 and turnoff LMFC 21.

Step 4: Repeat step 1 to 3 for anode 3 (turn on LMFC 22, valves 81, 83,84, and power supply 12, and turn off LMFCS 21 23,24, valve 82, powersupplies 11, 13, 14).

Step 5: Repeat step 4 for anode 2 (turn on LMFC 23, valves 81, 82, 84,and power supply 13, and turn off LMFCS 21, 22, 24, valve 83, and powersupplies 11, 12, 14).

Step 6: Repeat step 4 for anode 1 (turn on LMFC 24, valves 81, 82, 83,and power supply 14, and turn off LMFCS 21, 22, 23, valve 84, and powersupplies 11, 12, 13).

In the above seed layer plating process, instead of plating from theperiphery of the wafer to the center of the wafer, the plating also canbe performed from the center to the periphery, or can be performed witha randomly chosen anode sequence.

2B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 2A.

Step 7: Turn on LMFCS, 21, 22, 23 and 24 and turn off valves 81, 82, 83,84. In principle, the flow rate of electrolyte from each LMFC is set asproportional to the wafer area covered by the corresponding anode.

Step 8: After all flow is stabilized, turn on power supplies 11, 12, 13and 14. In principle, the current of each power supply is set asproportional to the wafer area covered by the corresponding anode.

Step 9: Turn off power supplies 11, 12, 13 and 14 at the same time whenplating current is used as thickness uniformity timing variable. Thepower supplies can also be turned off at different times for adjustingplating film thickness uniformity.

FIGS. 16A-16B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 16A-16B is similar to that of FIGS. 15A-15B except that on/offvalves 81, 82, 83, 84 are removed, and the electrolyte return path isreduced to only one between cylindrical walls 100 and 103.

3A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on LMFC 21 only, turn off LMFCS 22, 23, 24. The whole waferis immersed in the electrolyte. However, only the portion of wafer aboveanode 4 faces the flowing electrolyte from LMFC 21.

Step 2: After the flow of electrolyte stabilized, turn on power supply11 to output positive potential to electrode 4 and turn on powersupplies 12, 13, and 14 to output negative potential to electrode 3, 2,and 1, respectively. Therefore, positive metal ions will be plated onlyonto the portion of wafer 31 above anode 4.

Step 3: When the thickness of the conductive film reaches thepredetermined set-value or thickness, turn off power supply 11 and turnoff LMFC 21.

Step 4: Turn on LMFC 22 only, turn off LMFCS 21, 23, 24. In this way,even whole wafer area is immersed in the electrolyte, only the waferarea above anode 3 is facing the flowing electrolyte from LMFC 22.

Step 5: Repeat step 2 to 3 for anode 3 (turn on power supply 12 tooutput positive potential to anode 3, and power supplies 11, 13, and 14to output negative potential to anode 4, 2, and 1, and turn off LMFCS21, 23, 24).

Step 6: Repeat step 4 to 5 for anode 2 (turn on LMFC 23, and powersupply 13 to output positive potential to anode 2, and power supplies11, 12, and 14 to output negative potential to anode 4, 3, and 1, andturn off LMFCS 21, 22, 24).

Step 7: Repeat step 4 to 5 for anode 1 (turn on LMFC 24, and powersupply 14 to output positive potential to anode 1, and power supplies11, 12, and 13 to output negative potential to anode 4, 3 and 2, andturn off LMFCS 21, 22, 23).

In the above seed layer plating process, instead of plating from theperiphery of the wafer to the center of the wafer, the plating also canbe performed from the center to the periphery, or can be performed witha randomly chosen anode sequence.

3B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 3A

Step 8: Turn on LMFCS 21, 22, 23 and 24. In principle, the flow rate ofelectrolyte from each LMFC is set as proportional to the wafer areacovered by the corresponding anode.

Step 9: After all flow is stabilized, turn on power supplies 11, 12, 13and 14. In principle, the current of each power supply is set asproportional to the wafer area covered by the corresponding anode.

Step 10: Turn off power supplies 11, 12, 13 and 14 at the same time whenplating current is used as the thickness uniformity tuning variable.Also the power supplies can be turned off at different times foradjusting plating film thickness uniformity.

FIG. 17 shows another embodiment of apparatus for plating a conductivefilm in accordance with the present invention. The embodiment of FIG. 17is similar to that of FIGS. 3A-3B except that a diffuser ring 112 isadded above each anode to make the flow rate uniform along itscylindrical wall. The diffuser can be made by punching many holesthrough the diffuser ring, or directly made of porous materials withporosity range of 10% to 90%. The material for making the diffuser isanti-acid, anti-corrosion, particle and contamination free.

FIGS. 18A-18B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 18A-18B is similar to that of FIGS. 3A-3B except that a chargeaccumulator meter is added to each power supply to precisely measure thecharge each power supply provides during the plating process. Forinstance, the total number of atoms of copper can be calculated by theaccumulated charge divided by two, because copper ions have a valence oftwo.

FIGS. 19A-19B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 19A-19B is similar to that of FIGS. 3A-3B except that thenumber of electrolyte inlets to the plating bath is two instead of one.This will further enhance the flow rate uniformity along the peripheryof the cylindrical walls. The number of inlets also can be 3, 4, 5, 6, .. . i.e. any number larger than 2 in order to make the flow rate uniformalong the periphery of the cylindrical walls.

FIGS. 20A-20B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 20A-20B is similar to that of FIGS. 15A-15B and FIGS. 16A-16B,except that the height of the cylindrical walls is increasing along theoutward radial direction as shown in FIG. 20A, and is reduced along theoutward radial direction as shown in FIG. 20B. This provides aadditional variable to manipulate the flow pattern of electrolyte andplating current in order to optimize the plating conditions.

FIGS. 21A-21B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 21A-21B is similar to that of FIGS. 3A-3B except that theheight of the cylindrical walls is increasing along the outward radialdirection as shown in FIG. 21A, and is reducing along the outward radialdirection as shown in FIG. 21B. This provides an additional variable tomanipulate the flow pattern of electrolyte and plating current in orderto optimize the plating conditions.

FIGS. 22A-22B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 22A-22B is similar to that of FIGS. 3A-3B, except that thecylindrical walls can move up and down to adjust the flow pattern. Asshown in FIG. 22B, cylindrical walls 105 and 107 are moved up, so thatthe electrolyte flows toward the portion of wafer above wall 105 and107. Plating process steps are described as follows:

4A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on LMFC 21 only and move cylindrical walls 101, 103 closeto the wafer, so that electrolyte only touches the portion of the waferabove cylindrical walls 101 and 103.

Step 2: After the flow of electrolyte is stabilized, turn on powersupply 11. Positive metal ions will be plated onto the portion of wafer31 above cylindrical walls 101 and 103.

Step 3: When the thickness of the conductive film reaches thepredetermined set-value or thickness, turn off power supply 11, turn offLMFC 21, and move cylindrical walls 101 and 103 to a lower position.

Step 4: Repeat step 1 to 3 for cylindrical walls 105 and 107 (LMFC 22,cylindrical wall 105 and 107, and power supply 12).

Step 5: Repeat step 4 for tube 109 (LMFC 23, tube 109, and power supply13).

4B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 4A.

Step 6: Turn on LMFCS 21, 22, and 23, and move all cylindrical walls101, 103, 105, 107 and tube 109 close to wafer 31. In principle, theflow rate of electrolyte from each LMFC is set as proportional to thewafer area covered by the corresponding LMFC.

Step 7: After all flow is stabilized, turn on power supplies 11, 12, and13. In principle, the current from each power supply is proportional tothe wafer area covered by the corresponding anode or power supply.

Step 8: Turn off power supplies 11, 12, and 13 at the same time whenplating current is used as the thickness uniformity tuning variable. Thepower supplies also can be turned off at different times for adjustingplating film thickness uniformity.

FIGS. 23A-23B show another two embodiments of apparatus for plating aconductive film in accordance with the present invention. Theembodiments of FIGS. 23A and 23B are similar to those of FIGS. 15A-15Band FIGS. 3A-3B, except that the cylindrical walls and anode ring aredivided into six sectors by plate 113. The number of sectors can be anynumber larger than 2. The following table 2 shows possible combinationsof anode to power supply connections and each sector to an LMFC.

TABLE 2 Combina- Anode connection to power Sector connection tion typesupply in each sector to LMFC 1 Each anode is connected to an Eachsector is connected to an independent power supply independent LMFC 2Each anode is connected to an Sectors on the same radius are independentpower supply connected to an independent LMFC 3 Each anode is connectedto an All sectors are connected to independent power supply one commonLMFC 4 Anodes on the same radius are Each sector is connected to anconnected to an independent independent LMFC power supply 5 Anodes onthe same radius are Sectors on the same radius are connected to anindependent connected to an independent power supply LMFC 6 Anodes onthe same radius are All sectors are connected to connected to anindependent one common LMFC power supply 7 All anodes are connected toEach sector is connected to an one common power supply independent LMFC8 All anodes are connected to Sectors on the same radius are one commonpower supply connected to an independent LMFC 9 All anodes are connectedto All sectors are connected to one common power supply one common LMFC

In the above table, the operation of combination types 1, 2, 4, and 5are the same as described above. In the case of combination types 1, 2,and 3, the wafer rotating mechanism can be eliminated since each anodeat a different sector is controlled by an independent power supply. Forinstance, the thickness of the plating film on a portion of thesubstrate can be manipulated by controlling the plating current or theplating time of the anode below the same portion of the substrate. Theoperation of combination types 3, 6, 7, 8, 9 will be discussed later indetail.

FIGS. 24A-24B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 24A-24B is similar to that of FIGS. 3A-3B except that thecylindrical walls and anode ring are replaced by multiple rod typeanodes 1 and tubes 109. Electrolyte comes out of the tubes 109, touchesthe wafer surface, and then flows back to the tank (not shown) throughmultiple holes 500. The tubes and anodes in a ring are placed in thesame circle. There are multiple holes between two adjacent ring of tubesand anodes for draining electrolyte back to tank 36. The following table3 shows possible combinations of anode to power supply connection andeach sector to LMFC.

TABLE 3 Combina- Anode connection to power Tube connection tion typesupply in each tube to LMFC 1 Each anode is connected to an Each tube isconnected to an independent power supply independent LMFC 2 Each anodeis connected to an Tubes on the same radius are independent power supplyconnected to an independent LMFC 3 Each anode is connected to an Alltubes are connected to independent power supply one common LMFC 4 Anodeson the same radius are Each tube is connected to an connected to anindependent independent LMFC power supply 5 Anodes on the same radiusare Tubes on the same radius are connected to an independent connectedto an independent power supply LMFC 6 Anodes on the same radius are Alltubes are connected to connected to an independent one common LMFC powersupply 7 All anodes are connected to Each tube is connected to an onecommon power supply independent LMFC 8 All anodes are connected to Tubeson the same radius are one common power supply connected to anindependent LMFC 9 All anodes are connected to All tubes are connectedto one common power supply one common LMFC

In the above table, the operation of combination types 1, 2, 4, and 5are the same as described above. In the case of combination types 1, 2,and 3, the wafer rotating mechanism can be eliminated since each anodeat a different tube is controlled by an independent power supply. Forinstance, the thickness of plating film on a portion of the substratecan be manipulated by controlling the plating current or the platingtime of the anode below the same portion of the substrate. The operationof combination types 3, 6, 7, 8, 9 will be discussed later in detail.

Instead of placing tubes and anodes on a circular ring, the tubes andanodes also can be placed on triangular, square, rectangular,pentagonal, polygonal, and elliptical rings. Triangular, square andelliptical rings are shown in FIGS. 25A-25C.

2. Multiple LMFCs and Single Power Supply

FIGS. 26A-26B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 26A-26B is similar to that of FIGS. 3A-3B except that the anoderings and cylindrical walls are replaced by a single anode 240, bar 242and valves 202, 204, 206, 208, 210, 212, 214, 216 and 218. The powersupplies is reduced to a singe power supply 200. The new valves areon/off valves, and are used to control electrolyte flowing to the waferarea. Valves 208 and 212, 206 and 214, 204 and 216, 202 and 218 areplaced symmetrically on bar 242, respectively.

5A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on pump 33, LMFC 55, and valves 202 and 218 as well asdrive 30, so that electrolyte coming out of valves 202 and 218 onlytouches the peripheral portion of the wafer above valve 202 and 218.

Step 2: After the flow of electrolyte is stabilized, turn on powersupply 200. Positive metal ions will be plated onto the peripheralportion of wafer 31 above valve 202 and 218.

Step 3: When the thickness of the conductive film reaches thepredetermined set-value or thickness,turn off power supply 200 and turnoff LMFC 55, valves 202 and 218.

Step 4: Repeat step 1 to 3 for valves 204 and 216.

Step 5: Repeat step 4 for valves 206 and 214.

Step 6: Repeat step 4 for valves 208 and 212.

Step 7: Repeat step 4 for valves 210.

During the above plating process, the power supply can be operated in DCmode, or any of the variety of pulse modes shown in FIG. 8.

5B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 5A.

Step 8: Turn on LMFC 55 and all valves 202, 204, 206, 208, 210, 212,214, 216, 218, so that electrolyte touches the whole wafer area.

Step 9: After all flow is stabilized, turn on power supplies 200.

Step 10: Turn off power supply 200 and all the valves when the filmthickness reaches the set value. The valves can also be turned off atdifferent times with the power supply 200 turned on for adjusting theplating film thickness uniformity within the wafer.

FIG. 27 shows another embodiment of apparatus for plating conductivefilm in accordance with the present invention. The embodiment of FIG. 27is similar to that of FIGS. 26A-26B, except that all valves are placedon the bar 242 with a different radius in order to plate metal withbetter uniformity. Plating process steps are described as follows:

6A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on pump 33, LMFC 55, and valve 218 as well as drive 30, sothat electrolyte coming out of valve 218 only touches the peripheralportion of the wafer above valve 218.

Step 2: After the flow of electrolyte is stabilized, turn on powersupply 200. Positive metal ions will be plated onto the peripheralportion of wafer 31 above valve 218.

Step 3: When the thickness of the conductive film reaches thepredetermined set-value or thickness, turn off power supply 200, LMFC 55and valve 218.

Step 4: Repeat step 1 to 3 for valve 204.

Step 5: Repeat step 4 for valve 216.

Step 6: Repeat step 4 for valve 206

Step 7: Repeat step 4 for valves 214, 208, 212, and 210, respectively.

During the above plating process, the power supply 200 can be operatedin DC mode or any of the variety of pulse modes shown in FIG. 8.

6B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 6A.

Step 8: Turn on LMFC 55 and all valves 204, 206, 208, 210, 212, 214,216, 218, so that electrolyte touches the whole wafer area.

Step 9: After all flow is stabilized, turn on power supply 200.

Step 10: Turn off power supply 200 and all valves when the filmthickness reaches the set value. The valves can also be turned off atdifferent times with the power supply 200 turned on for adjustingplating film thickness uniformity within the wafer.

FIG. 28 shows another embodiment of apparatus for plating a conductivefilm in accordance with the present invention. The embodiment of FIG. 28is similar to that of FIG. 26 except that an additional bar is added toform a cross shape bar structure 244. Valves 202 and 218, 204 and 216,206 and 214, 208 and 212 are placed symmetrically on the horizontalportion of bar structure 244. Similarly, valves 220 and 236, 222 and234, 224 and 232 are placed symmetrically on the vertical portion of thebar structure 244. All valves on the horizontal portion of bar 244 alsohave a different radius from those on the vertical portion of bar 244,respectively. Plating process steps are described as follows:

7A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on pump 33, LMFC 55, and valve 218 and 202 as well as drive30, so that electrolyte coming out of valves 218 only touches theperipheral portion of the wafer above valves 218 and 202.

Step 2: After the flow of electrolyte is stabilized, turn on powersupply 200. Positive metal ions will be plated onto the peripheralportion of wafer 31 above valves 218 and 202.

Step 3: When the thickness of the conductive film reaches thepredetermined set-value or thickness, turn off power supply 200, LMFC 55and valves 218 and 202.

Step 4: Repeat step 1 to 3 for valves 220 and 236.

Step 5: Repeat step 4 for valves 204 and 216.

Step 6: Repeat step 4 for valves 222 and 234.

Step 7: Repeat step 4 for valves 206 and 214, 224 and 232, 208 and 212,and 210 only, respectively.

During the above plating process, the power supply can be operated in DCmode, or any of the variety of pulse modes shown in FIG. 8.

7B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 7A.

Step 8: Turn on LMFC 55 and all valves 202, 204, 206, 208, 210, 212,214, 216, 218, 220, 222, 224, 232, 234, 236,so that electrolyte touchesthe whole wafer area.

Step 9: After all flow is stabilized, turn on power supply 200.

Step 10: Turn off power supply 200 and all valves when the filmthickness reaches the set value. The valves can also be turned off atdifferent times with the power supply 200 turned on for adjustingplating film thickness uniformity within the wafer.

FIGS. 29A-29C show portions of an additional three embodiments ofapparatus for plating a conductive film in accordance with the presentinvention. The embodiment of FIG. 29A is similar to that of FIGS.26A-26B except that the number of bars is increased to three. The anglebetween two adjacent bars is 60°. The embodiment of FIG. 29B is similarto that of FIGS. 26A-26B except that the number of bars is increased tofour. The angle between two adjacent bars is 45°. The embodiment of FIG.29C is similar to that of FIGS. 26A-26B except that the bar is reducedto 0.5, i.e. half a bar. Alternatively, the number of bars can be 5, 6,7, or more.

The plating step sequence can be started from valves close to theperiphery of the wafer, or started from the center of the wafer, orstarted randomly. Starting from the periphery of the wafer is preferredsince the previously plated metal seed layer (with a larger diameter)can be used to conduct current for plating the next seed layer (with asmaller diameter).

FIGS. 30A-30B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 30A-30B is similar to that of FIGS. 26A-26B except that fixedposition valves (jet) are replaced by two movable anode jets 254. Anodejets 254 are placed under wafer 31 and sit on guide bar 250. Anode jets254 inject electrolyte onto a portion of wafer 31, and can move in the xdirection as shown in FIG. 30B. Fresh electrolyte is supplied throughflexible pipe 258. This embodiment is especially preferred for plating aseed layer. The seed layer plating process is shown as follows:

8A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on pump 33, LMFC 55 and valves 356 as well as drive 30, sothat electrolyte coming out of valves 356 only touches the peripheralportion of the wafer above valves 356.

Step 2: After the flow of electrolyte is stabilized, turn on powersupply 200. Positive metal ions will be plated onto the peripheralportion of wafer 31 above valves 356.

Step 3: When the thickness of the conductive film reaches thepredetermined set-value or thickness, turn off power supply 200, LMFC55, and valves 356.

Step 4: Move anode jet 254 to the next position with a smaller radius;

Step 5: Repeat step 1 to 4 until the whole wafer area is plated by thethin film.

The above process steps can be modified as follows:

Step 1: Same as above

Step 2: Same as above

Step 3: When the thickness of the conductive film reaches a certainpercentage of the predetermined set-value or thickness, start slowlymoving anode jet 254 radially toward the wafer center. The rate ofmoving the anode jet 254 is determined by the predetermined set-value orthickness. Also since the surface area plated by the anode jet 254 isproportional to the radius of the position of anode jet 254, the rate ofmoving anode jet 254 increases as it moves toward the wafer center.

Step 4: When anode jet 254 reaches the wafer center, turn off powersupply 200, LMFC 55, and valves 356.

FIGS. 31A-31B shows another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 31A-31B is similar to that of FIGS. 30A-30B except that twoadditional movable anode jets are added in the Y direction in order toincreasing plating speed. The process sequence is similar to that of theFIGS. 30A-30B embodiment.

FIGS. 32A-32B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 32A-32B is similar to that of FIGS. 30A-30B except that wafer31 is immersed into the electrolyte. A movable anode is placed veryclose to the wafer 31 in order to focus plating current on a portion ofwafer 31. The gap size is in a range of 0.1 mm to 5 mm, and preferably 1mm. The process sequence is similar to that of the FIG. 30 embodiment.

FIGS. 33A-33B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 33A-33B is similar to that of FIGS. 32A-32B except that freshelectrolyte is input from the center of the bath through pipes 260instead of anode jets 254 through flexible pipe 258. Wafer 31 is alsoimmersed into the electrolyte. Similarly, a movable anode is placed veryclose to wafer 31 in order to focus plating current on a portion ofwafer 31. The gap size is in a range of 0.1 mm to 5 mm, and preferably 1mm. The process sequence is similar to that of FIG. 30.

FIGS. 34A-34D show four embodiments of movable anodes in accordance withthe present invention. FIG. 34A shows an anode structure consisting ofanode 252 and case 262. Case 262 is made of insulator materials such astetrafluoroethylene, PVC, PVDF, or polypropylene. FIG. 34B shows ananode structure consisting of anode 266 and case 264. The electrolyte isfeed through a hole at the bottom of case 264. FIG. 34C shows an anodestructure consisting of anode 262, electrodes 274 and 270, insulatorspacer 272 and case 262, and power supplies 276, 268. Electrode 274 isconnected to negative output of power supply 276, and electrode 270 isconnected to cathode wafer 31. The function of electrode 274 is to trapany metal ions flowing out of case 262, therefore no film is plated onthe wafer area outside of case 262. The function of electrode 270 is toprevent electrical field leakage from electrode 274 to minimize anyetching effect. The embodiment of FIG. 34D is similar to that of FIG.34C except that the case 264 has a hole at the bottom for electrolyte toflow through.

FIG. 35 shows the surface status of a wafer during plating. Wafer area280 was plated by a seed layer, area 284 is in the process of plating,and wafer area 282 has not been plated.

FIGS. 36A-36C show an additional three embodiments of apparatus forplating a conductive film in accordance with the present invention. Theembodiment of FIG. 36A is similar to that of FIGS. 30A-30B except thatthe number of bars is increased to three. The angle between two adjacentbars is 60°. The embodiment of FIG. 36B is similar to that of FIGS.30A-30B except that the number of bars is increased to four. The anglebetween two adjacent bars is 45°. The embodiment of FIG. 36C is similarto that of FIGS. 30A-30B except that the number of bars is reduced to0.5, i.e. half a bar. Alternatively, the number of bars can be 5, 6, 7or more.

The embodiment of FIG. 36D is similar to that of FIGS. 30A-30B exceptthat the shape of bar 250 is a spiral instead of a straight line.Movable anode jet 254 is movable along the spiral bar so that goodplating uniformity can be achieved without rotating the wafer. Thissimplifies the wafer chuck mechanism.

FIGS. 37A and 37B show additional two embodiments of apparatus forplating a conductive film in accordance with the present invention. Theembodiments of FIG. 37A and 37B are similar to that of FIGS. 30A-30B,except that the wafer is placed upside down and vertically,respectively.

FIGS. 38A-38B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 38A-38B is similar to that of FIGS. 16A-16B except that all ofthe anodes are replaced by a one piece anode 8. Anode 8 is connected tosingle power supply 11. Plating process steps using this embodiment aredescribed as follows:

9A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on LMFC 21. and valves 82, 83, and 84 and turn off LMFCS22, 23, 24 and valve 81, so that electrolyte only touches the portion ofthe wafer above sub-plating bath 66, and then flows back to tank 36through the return paths of spaces between cylindrical walls 100 and103, 105 and 107, 107 and 109, and tube 109.

Step 2: After the flow of electrolyte is stabilized, turn on powersupply 11. Positive metal ions will be plated onto the portion of wafer31 above sub-plating bath 66.

Step 3: When the thickness of the conductive film reaches thepredetermined set-value or thickness, turn off power supply 11 and turnoff LMFC 21.

Step 4: Repeat step 1 to 3 for LMFC 22 (turn on LMFC 22, valves 81, 83,84, and power supply 11, and turn off LMFCs 21 23, 24, valve 82).

Step 5: Repeat step 4 for LMFC 23 (turn on LMFC 23, valves 81, 82, 84,and power supply 11, and turn off LMFCs 21, 22, 24, valve 83).

Step 6: Repeat step 4 for LMFC 24 (turn on LMFC 24, valves 81, 82, 83,and power supply 11, and turn off LMFCs 21, 22, 23 and valve 84).

In the above seed layer plating process, instead of plating from theperiphery of the wafer to the center of the wafer, the plating also canbe performed from the center to the periphery, or can be performed in arandomly chosen anode sequence.

9B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 9A.

Step 7: Turn on LMFCs 21, 22, 23 and 24 and turn off valves 81, 82, 83,84. In principle, the flow rate of electrolyte from each LMFC is set asproportional to the wafer area covered by the corresponding LMFC.

Step 8: After all flows are stabilized, turn on power supply 11.

Step 9: Turn off power supply 11 when the film thickness reaches theset-value.

LMFCs can be turned off at different times in order to adjust theplating film thickness uniformity as shown in FIG. 39. At time t₁, onlyLMFCs 21, 23, and 24 are turned off, and valves 81, 83, and 84 are alsoturned off. Therefore, electrolyte does not touch the wafer except inthe area above sub-plating bath 64. As the power supply 11 remainsturned on, metal ions will be plated only on the area above sub-platingbath 64. Then LMFC 22 turns off at time t₂. Similarly, LMFC 24 turns onat time t₃ and turns off at time t₄ to obtain extra plating at the waferarea above sub-plating bath 60. Turn off time of t₂ and t₄ can be finetuned by measuring wafer thickness uniformity.

FIGS. 40A-40B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 40A-40B is similar to that of FIGS. 3A-3B except that allanodes are connected to single power supply 11. Since the electrolyteonly touches the portion of wafer above an anode during the seed layerplating process, the plating current will only pass through the anodeand go to that portion of the wafer. The plating process steps aresimilar to those of FIGS. 3A-3B with power supply 11 replacing powersupplies 12 and 13.

FIGS. 41A-41B show another embodiment of apparatus for plating aconductive film in accordance with the present invention. The embodimentof FIGS. 41A-41B is similar to that of FIGS. 40A-40B except that thecylindrical walls can move up and down to adjust the flow pattern. Asshown in FIG. 41B, cylindrical walls 105 and 107 are moved up, so thatthe electrolyte flows toward the portion of wafer above walls 105 and107. The plating process steps for this embodiment are described asfollows:

10A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on LMFC 21 only and move cylindrical walls 101, 103 closeto the wafer, so that electrolyte only touches the portion of the waferabove cylindrical walls 101 and 103.

Step 2: After the flow of electrolyte stabilized, turn on power supply11. Positive metal ions will be plated onto the portion of wafer 31above cylindrical walls 101 and 103.

Step 3: When the thickness of the conductive film reaches thepredetermined set-value or thickness, turn off power supply 11 and LMFC21, and move cylindrical walls 101 and 103 to a lower position.

Step 4: Repeat step 1 to 3 for cylindrical walls 105 and 107 (LMFC 22,cylindrical walls 105 and 107).

Step 5: Repeat step 4 for tube 109 (LMFC 23 and tube 109).

10B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 10A.

Step 6: Turn on LMFC 21, 22, and 23, and move all cylindrical walls 101,103, 105, 107 and tube 109 close to wafer 31. In principle, the flowrate of electrolyte from each LMFC is set as proportional to the waferarea covered by the corresponding LMFC.

Step 7: After all flows are stabilized, turn on power supplies 11.

Step 8: Move all cylindrical walls down to their lower position, andturn off all LMFCs at the same time, then turn off power supplies 11when the film thickness reaches the predetermined set-value. Each pairof cylindrical walls can also be moved down at different times withpower supply 11 on in order adjust thickness uniformity. For example, asshown in FIG. 41B, cylindrical walls 105 and 107 are being kept at thehigher position with LMFC 22 on. The wafer area above cylindrical walls105 and 107 will have extra plating film on that portion. The extraplating times and locations can be determined by analyzing the thicknessuniformity of the plated film on the wafer.

3. Multiple Power Supplies and Single LMFC

FIGS. 42A-42B is an embodiment of the apparatus with multiple powersupplies and a single LMFC for plating a conductive film directly on asubstrate with a barrier layer on top in accordance with the presentinvention. The embodiment of FIGS. 42A-42B is similar to that of FIG.16A-16B except that LMFCs 21, 22, 23 and 24 are replaced by a singleLMFC 55.

11A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on LMFC 55 and immerse the whole wafer in the electrolyte.

Step 2: After the flow of electrolyte is stabilized, turn on powersupply 11 to output positive potential to electrode 4, and turn on powersupplies 12, 13, and 14 to output negative potential to electrodes 3, 2,and 1, respectively. Therefore, positive metal ions will be plated onlyonto the portion of wafer 31 above anode 4.

Step 3: When the thickness of the conductive film reaches thepredetermined set-value or thickness, turn off power supply 11.

Step 4: Repeat steps 2 to 3 for anode 3 (turn on power supply 12 tooutput positive potential to anode 3, and power supplies 11, 13, and 14to output negative potential to anodes 2 and 1).

Step 5: Repeat step 4 for anode 2 (turn on power supply 13 to outputpositive potential to anode 2, and power supply 14 to output negativepotential to anode 1).

Step 6: Repeat step 4 for anode 1 (turn on power supply 14 to outputpositive potential to anode FIG. 43 shows the power supply turn on/offsequence for plating wafer areas 4 (above anode 4), 3, 2, and 1. The,power supply output wave forms can be selected from a variety of waveforms, such as a modified sine-wave form, a unipolar pulse, a reversepulse, a pulse-on-pulse or a duplex pulse, as shown in FIG. 44.

In the above seed layer plating process, instead of plating from theperiphery of the wafer to the center of the wafer, the plating also canbe performed from the center to the periphery, or can be performed witha randomly chosen anode sequence.

11B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 11A

Step 7: Turn on LMFC 55.

Step 8: After all flows are stabilized, turn on power supplies 11, 12,13 and 14. In principle, tile current of each power supply is set asproportional to the wafer area covered by the corresponding anode.

Step 9: Turn off power supplies 11, 12, 13 and 14 at the same time whenplating current is used as thickness uniformity tuning variable.Alternatively, the power supplies can be turned off at different timesfor adjusting plating film thickness uniformity.

FIG. 45A-45B is an other embodiment of an apparatus with multiple powersupplies and a single LMFC for plating a conductive film directly on asubstrate with a barrier layer on top in accordance with the presentinvention. The embodiment of FIGS. 45A-45B is similar to that of FIGS.42A-42B except that the cylindrical walls can move up and down to adjustflow pattern. As shown in FIG. 45B, cylindrical walls 105 and 107 aremoved up, so that the electrolyte flows toward the portion of the waferabove walls 105 and 107. The plating process steps with this embodimentare described as follows:

12A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on LMFC 55 and move cylindrical walls 101, 103 close to thewafer, so that electrolyte only touches the portion of the wafer abovecylindrical walls 101 and 103.

Step 2: After the flow of electrolyte is stabilized, turn on powersupply 11. Positive metal ions will be plated onto the portion of wafer31 above cylindrical walls 101 and 103.

Step 3: When the thickness of the conductive film reaches thepredetermined set-value or thickness, turn off power supply 11, and movecylindrical walls 101 and 103 to a lower position.

Step 4: Repeat step 1 to 3 for cylindrical walls 105 and 107(cylindrical walls 105 and 107, and power supply 12).

Step 5: Repeat step 4 for tube 109 (tube 109, and power supply 13).

12B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 12A.

Step 6: Turn on LMFC 55, and move all cylindrical walls 101, 103, 105,107 and tube 109 close to wafer 31.

Step 7: After all flows are stabilized, turn on power supplies 11, 12,and 13. In principle, the current from each power supply is proportionalto the wafer area covered by the corresponding anode or power supply.

Step 8: Turn off power supplies 11, 12, and 13 at the same time whenplating current is used as the thickness uniformity tuning variable.Alternatively, the power supplies can be turned off at different timesfor adjusting plating film thickness uniformity.

FIGS. 46A-46B is another embodiment of an apparatus with multiple powersupplies and a single LMFC for plating a conductive film directly on asubstrate with a barrier layer on top in accordance with the presentinvention. The embodiment of FIGS. 46A-46B is similar to that of FIGS.42A-42B except that the height of the cylindrical wall is reduced alongthe outward radial direction as shown in FIG. 46B. The shape or flowpattern of the electrolyte can be adjusted by moving cylindrical wall120 up or down. When the cylindrical wall is moved to the highestposition, the whole wafer area will be touched by the electrolyte,whereas the center portion of the wafer will be touched by theelectrolyte when the cylindrical wall 120 is moved to the lowestposition. The plating process steps with this embodiment are describedas follows:

13A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on LMFC 55 and move cylindrical wall 120 to the highestposition, so that the electrolyte touches the whole area of wafer 31.

Step 2: After the flow of electrolyte is stabilized, turn on powersupply 11 to output positive potential to anode 4, and turn on powersupplies 12, 13 and 14 to output negative potential to anodes 3, 2, and1, respectively. Therefore, positive metal ions will be plated only ontothe peripheral portion of wafer 31 above anode 4.

Step 3: When the thickness of the conductive film on the peripheralportion of the wafer reaches the predetermined set-value or thickness,turn off power supply 11.

Step 4: Move cylindrical wall 120 to a lower position so that only theperipheral portion of the wafer plated by the metal thin film in step 3is out of the electrolyte.

Step 5: Repeat steps 2 to 3 for anode 3 (turn on power supply 12 tooutput positive potential to anode 3, and turn on power supplies 13 and14 to output negative potential to anodes 2 and 1).

Step 6: Move cylindrical wall 120 to the next lower position so thatonly the peripheral portion of the wafer plated by the metal thin filmin step 5 is out of the electrolyte.

Step 7: Repeat step 2 to 3 for anode 2 (turn on power supply 13 tooutput positive potential to anode 2, and turn on power supply 14 tooutput negative potential to anode 1).

Step 8: Move cylindrical wall 120 to the next lower position so thatonly the peripheral portion of the wafer plated by the metal thin filmin step 7 is out of the electrolyte.

Step 9: Repeat step 2 to 3 for anode 1 (turn on power supply 14 tooutput positive potential to anode 1).

13B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 13A.

Step 10: Turn on LMFC 55, and move cylindrical wall 120 to the highestposition, so that whole area of wafer 31 is touched by the electrolyte.

Step 11: After flow is stabilized, turn on power supplies 11, 12, 13,and 14. In principle, the current from each power supply is proportionalto the wafer area covered by the corresponding anode or power supply.

Step 12: Turn off power supplies 11, 12, 13, and 14 at the same timewhen plating current is used as thickness uniformity tuning variable.Alternatively, each power supply can be turned off at a different timefor adjusting the film thickness uniformity.

FIGS. 47A-47B is another embodiment of an apparatus with multiple powersupplies and a single LMFC for plating a conductive film directly on asubstrate with a barrier layer on top in accordance with the presentinvention. The embodiment of FIGS. 47A-47B is similar to that of FIGS.46A-46B except that the position of cylindrical wall 120 is fixed andthe level of the electrolyte is changed by adjusting the flow rate ofthe electrolyte. When the flow rate of the electrolyte is large, theelectrolyte level is high, so that the whole wafer area is touched bythe electrolyte. When the flow rate is small, the electrolyte level islow, so that the peripheral portion of wafer 31 is out of theelectrolyte as shown in FIG. 47B. The plating process steps with thisembodiment are described as follows:

14A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on LMFC 55 and to set a flow rate sufficiently large thatthe electrolyte touches the whole area of wafer 31.

Step 2: After the flow of electrolyte is stabilized, turn on powersupply 11 to output positive potential to anode 4, and turn on powersupplies 12, 13 and 14 to output negative potential to anodes 3, 2, and1, respectively. Therefore, positive metal ion will be plated only ontothe peripheral portion of wafer 31 above anode 4.

Step 3: When the thickness of the conductive film on the peripheralportion of the wafer reaches the set-value or thickness, turn off powersupply 11.

Step 4: Reduce the flow rate of the electrolyte to such a value thatonly the peripheral portion of the wafer plated by the metal thin filmin step 3 is out of the electrolyte.

Step 5: Repeat steps 2 to 3 for anode 3 (turn on power supply 12 tooutput positive potential to anode 3, and turn on power supplies 13 and14 to output negative potential to anodes 2 and 1).

Step 6: Reduce the flow rate of the electrolyte so that only theperipheral portion of the wafer plated by the metal thin film in step 5is out of the electrolyte.

Step 7: Repeat steps 2 to 3 for anode 2 (turn on power supply 13 tooutput positive potential to anode 2, and turn power supply 14 to outputnegative potential to anode 1).

Step 8: Reduce the flow rate of the electrolyte so that only theperipheral portion of the wafer plated by the metal thin film in step 7is out of the electrolyte.

Step 9: Repeat steps 2 to 3 for anode 1 (turn on power supply 14 tooutput positive potential to anode 1).

14B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 14A.

Step 10: Increase the flow rate of the electrolyte so that the wholearea of wafer 31 is touched by the electrolyte.

Step 11: After flow is stabilized, turn on power supplies 11, 12, 13,and 14. In principle, the current from each power supply is proportionalto the wafer area covered by the corresponding anode or power supply.

Step 12: Turn off power supplies 11, 12, 13, and 14 at the same timewhen plating current is used as the thickness uniformity tuningvariable. Alternatively, each power supply can be turned off at adifferent time for adjusting the film thickness uniformity.

FIGS. 48A-48B is another embodiment of an apparatus with multiple powersupplies and a single LMFC for plating a conductive film directly on asubstrate with a barrier layer on top in accordance with the presentinvention. The embodiment of FIGS. 48A-48B is similar to that of FIGS.47A-47B except that the level of electrolyte is fixed and the wafer 31itself can be moved up and down to adjust the size of the wafer areacontacted by the electrolyte. When wafer 31 is moved to the lowestposition, the whole wafer area is touched by the electrolyte. When thewafer is moved to the highest position, only the center area of wafer 31is contacted by the electrolyte as shown in FIG. 48B. The platingprocess steps with this embodiment are described as follows:

15A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on LMFC 55, and move wafer 31 to such a position that theelectrolyte contacts the whole area of wafer 31.

Step 2: After the flow of electrolyte is stabilized, turn on powersupply 11 to output positive potential to anode 4, and turn on powersupplies 12, 13 and 14 to output negative potential to anodes 3, 2, and1, respectively. Therefore, positive metal ions will be plated only ontothe peripheral portion of wafer 31 above anode 4.

Step 3: When the thickness of the conductive film on the peripheralportion of the wafer reaches the predetermined set-value: or thickness,turn off power supply 11.

Step 4: Move wafer 31 up to a position such that only the peripheralportion of the wafer plated by the metal thin film in step 3 is out ofcontact with the electrolyte.

Step 5: Repeat step 2 to 3 for anode 3 (turn on power supply 12 tooutput positive potential to anode 3, and turn power supplies 13 and 14to output negative potential to anodes 2 and 1).

Step 6: Move wafer 31 up to a position such that only the peripheralportion of the wafer plated by the metal thin film in step 5 is out ofcontact with the electrolyte.

Step 7: Repeat step 2 to 3 for anode 2 (turn on power supply 13 tooutput positive potential to anode 2, and turn on power supply 14 tooutput negative potential to anode 1).

Step 8: Move wafer 31 up to a position such that only the peripheralportion of the wafer plated by the metal thin film in step 7 is out ofcontact with the electrolyte.

Step 9: Repeat step 2 to 3 for anode 1 (turn on power supply 14 tooutput positive potential to anode 1).

15B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 15A.

Step 10: Move wafer 31 down to a position such that the whole area ofwafer 31 is contacted by the electrolyte.

Step 11: After flow is stabilized, turn on power supplies 11, 12, 13,and 14. In principle, the current from each power supply is proportionalto the wafer area covered by the corresponding anode or power supply.

Step 12: Turn off power supplies 11, 12, 13, and 14 at the same timewhen plating current is used as thickness uniformity tuning variable.Alternatively, each power supply can be turned off at a different timefor adjusting the film thickness uniformity.

4. Single Power Supply and Single LMFC

FIGS. 49A-49B is another embodiment of an apparatus with a single powersupply and a single LMFC for plating a conductive film directly on asubstrate with a barrier layer on top in accordance with the presentinvention. The embodiment of FIGS. 49A-49B is similar to that of FIG.45A-45B except that the number of power supplies is reduced to one, andall the anodes are connected to single power supply 11. Similarly, thecylindrical walls can move up and down to adjust the flow pattern. Asshown in FIG. 49B, cylindrical walls 105 and 107 are moved up, so thatthe electrolyte flows toward the portion of wafer above walls 105 and107. The plating process steps with this embodiment are described asfollows:

16A. Process Steps for Plating Conductive Film (or Seed Layer) Directlyon Barrier Layer.

Step 1: Turn on LMFC 55 and move cylindrical walls 101, 103 close towafer, so that the electrolyte only contacts the portion of the waferabove cylindrical walls 101 and 103.

Step 2: After the flow of electrolyte is stabilized, turn on powersupply 11. Positive metal ions will be plated onto the portion of wafer31 above cylindrical walls 101 and 103.

Step 3: When the thickness of the conductive film reaches thepredetermined set-value or thickness, turn off power supply 11, and movecylindrical walls 101 and 103 to a lower position.

Step 4: Repeat step 1 to 3 for cylindrical walls 105 and 107 (movecylindrical walls 105 and 107 up close to wafer 31, and turn on powersupply 11).

Step 5: Repeat step 4 for tube 109 (move tube 109 up to close to wafer31, and turn on power supply 11).

16B. Process Steps for Succeeding Metal Plating on the Metal Seed LayerPlated in Process 16A.

Step 6: Turn on LMFC 55, and move all cylindrical walls 101, 103, 105,107 and tube 109 up to close to wafer 31.

Step 7: After all flows are stabilized, turn on power supply 11.

Step 8: Move all cylindrical walls down to lower position at the sametime, then turn off power supply 11 when the film thickness reaches thepredetermined set-value. Each pair of cylindrical walls can also bemoved down at different times with power supply 11 on in order adjustthe thickness uniformity. For example, as shown in FIG. 49B, cylindricalwalls 105 and 107 are kept at the higher position with power supply 11on. The wafer area above cylindrical walls 105 and 107 will have extraplating film on that portion. The extra plating time length and locationcan be determined by analyzing the thickness uniformity of the film onthe wafer through later film characterization.

5. Other Possible Combinations

A flow rate adjuster, such as the diffuser of the FIG. 17 embodiment maybe inserted into all embodiments that use a single LMFC. Multiple stagefilters, such as two filters connected in series, the first one a roughfilter for filtering particles larger than 1 μm, the second one a finefilter for filtering particles larger than 0.1 μm, may be employed.Also, instead of rotating the wafer, the plating bath can be rotatedduring plating in order to obtain good film uniformity within the wafer.In this case, a slip ring for conducting plating current, which is alsoconfigured to transport the electrolyte, should be used. Alternatively,a separate structure for transporting the electrolyte could be used.

An situ thickness uniformity monitor can be added to the plating bathsin accordance with the present invention as shown in FIG. 50. Onethickness detector 500 is set under each sub-plating bath or channel atthe different radii. After detecting thickness signals, detector 500transmits the signals to computer 502. Computer 502 processes thesignals and outputs the thickness uniformity. Also the wafer rotationposition can be input to computer 500 to locate the position along theperipheral direction. In this case, the bottom of the plating bath ismade of transparent material or has a window for a laser beam to passthrough.

FIG. 51 is another embodiment of an apparatus with a thicknessuniformity monitor. This embodiment is similar to the embodiment of FIG.50 except that optical fiber 504 is used. A laser beam from detector 500passes through the optical fiber 504 to the wafer. The laser beamreflected from the wafer also passes through optical fiber 504 andreturns to detector 500. The advantage of this embodiment is that thebottom of plating bath does not need to be made of transparent material.

A variety of metals can be plated by using the apparatus and methods ofthe invention. For example, Copper, Nickel, Chromium, Zinc, Cadmium,Silver, Gold, Rhodium, Palladium, Platinum, Tin, Lead, Iron and Indiumcan all be plated with the invention.

In the case of plating copper, three type of electrolytes are used,Cyanide, acid, and Pyrophosphate complex electrolytes. The basiccomposition of Cyanide copper electrolyte is: Copper cyanide; Sodiumcyanide, Sodium carbonate, Sodium hydroxide, and Rochelle salt. Thebasic composition of acid copper electrolyte is: Copper sulfate,Sulfuric acid, Copper fluoborate, Fluoboric acid, and Boric acid. Thebasic composition of pyrophosphate copper electrolyte is: Copperpyrophosphate, Potassium pyrophosphate, Ammonium nitrate, and Ammonia.Considering the process integration, acid copper electrolyte ispreferred for plating copper on a semiconductor wafer.

In the case of plating silver, a cyanide electrolyte is used. The basiccomposition of cyanide electrolyte is: Silver cyanide, Potassiumcyanide, Potassium carbonate, Potassium hydroxide, and Potassiumnitrate.

In the case of plating gold, a cyanide electrolyte is used. The basiccomposition of cyanide electrolyte is: Potassium gold cyanide, Potassiumcyanide, Potassium carbonate, Dipotassium monohydrogen phosphate,Potassium hydroxide, Monopotassium dihydrogen phosphate, and Potassiumnitrate.

Additives can used to enhance film quality in terms of smooth surface,small grain size, reducing the tendency to tree, small film stress, lowresistively, good adhesion, and better gap filling capability. In thecase of acid copper plating, the following materials may be used asadditives: glue, dextrose, phenolsulfonic acid, molasses, and thiourea.Additives for cyanide copper plating, include compounds having activesulfur groups and/or containing metalloids such as selenium ortellurium; organic amines or their reaction products with active sulfurcontaining compounds; inorganic compounds containing such metals asselenium, tellurium, lead, thallium, antimony, arsenic; and organicnitrogen and sulfur heterocyclic compounds.

5. System Architecture Design (Stacked Structure)

FIGS. 52A-52C are schematic views of an embodiment of a plating systemfor plating a conductive film on semiconductor wafer in accordance withthe present invention. It is a stand alone, fully computer controlledsystem with automatic wafer transfer and a cleaning module with waferdry-in and dry-out capability. It consists of five stacked plating baths300, 302, 304, 306, 308, five stacked cleaning/dry chambers 310, 312,314, 316, 318, robot 322, wafer cassette 321, 322, electrolyte tank 36and plumbing box 330. As described above, plating bath 300 consists ofanodes, cylindrical walls or tube, wafer chuck and a driver to rotate oroscillate wafers during the plating process. Electrolyte tank 36includes a temperature control. Plumbing box 330 consists of a pump,LMFCs, valves, a filter, and plumbing connections. The plating systemfurther includes computer control hardware, a power supply and anoperating system control software package. Robot 322 has a largez-travel. A telescopic type (stacked) robot with global positioningcapability made by Genmark Automation, Inc. is preferred. The operationprocess sequence for this embodiment is described as follows:

Single Wafer Plating Operation Sequence

Step A: Load wafer cassette 320,321 into the plating tool manually orwith a robot.

Step B: Select recipe and begin a process run.

Step C: The control software initializes the system including checkingall system parameters within the recipe specification, and determiningthat there are no system alarms.

Step D: After completing the initialization, robot 322 picks up a waferfrom cassette 320 or 321 and sends it to one of the plating baths (300,or 302, or 304, or 306, or 308).

Step E: Plating metal film on the wafer.

Step F: After finishing plating, robot 322 pick up the plated wafer fromthe plating bath, and transports it to one of the cleaning/dryingchambers (310, or 312, or 314, or 316, or 318).

Step G: Cleaning the plated wafer.

Step H: Drying the plated wafer through spin-dry and/or N₂ purge.

Step I: Robot 322 picks up the dried wafer and transport it to cassette320 or 321.

FIG. 53 shows the process sequence for plating multiple waferssimultaneously. The process sequence for plating multiple wafers issimilar to that for plating a single wafer except that the computerchecks if there is any unprocessed wafer remaining in cassette 320 or321 after process step I. If there is no unprocessed wafer remaining incassette 320 or 321, then the system loops back to step A, i.e. loadingnew cassettes or exchange cassettes. If there is still an unprocessedwafer remaining in cassette 320 and/or 321, then system will loop backto step D, i.e. robot 322 picks the unprocessed wafer from cassette andtransports it to one of the plating baths.

Process step E may include two process steps, a first to plate a seedlayer directly on the barrier layer and a second to plate a metal filmon the plated seed layer.

Instead of carrying out seed layer plating and the metal plating on theseed layer in one bath, the two process steps can be performed atdifferent baths. The advantages of doing two process steps in differentbaths is to give better process control or a wider process window, sincethe electrolyte for seed layer plating may be different from that forsucceeding plating on the seed layer. Here, different electrolyte meansdifferent acid type, different concentration of acid, differentadditives, different concentration of additives or different processtemperature. Also, the plating hardware may be different, consideringseed layer plating needs, such as high density nuclear sites, smoothmorphology, becoming a continuous film at very early stage (< a fewhundred Å), and need for a conformal layer. The succeeding plating onthe seed layer needs a high plating rate, single crystal structure,particular grain orientation, and gap filling without voids.

Instead of cleaning, wafers in one chamber, the cleaning process can beperformed in different chambers. The cleaning process may consists ofseveral steps, with each step using different solutions or a differentconcentration of solution, or using different hardware. Instead ofmounting robot 322 on the bottom of frame 301, robot 322 can be hungupside down onto the top of frame 301.

Instead of arranging five plating baths and five cleaning/dryingchambers, the number of plating bath and number of cleaning/drying canbe varied from 1 to 10 as shown in the following table.

Type 1 2 3 4 5 6 7 8 9 No. of plating bath 1 2 3 4 5 6 7 8 9 No. ofcleaning/drying 9 8 7 6 5 4 3 2 1 chamber

The preferred range is shaded in the above table.

FIGS. 54A-54C are schematic views of another embodiment of a platingsystem for plating a conductive film on a semiconductor wafer inaccordance with the present invention. The FIGS. 54A-54C embodiment issimilar to the embodiment of FIGS. 52A-52C except that the cassette 320is moved up and down by a robot 323. The position of cassette 320 ismoved up and down to match the position of the robot, so that robot 322does not need move in the Z direction when picking up an unprocessedwafer from cassette 320 or putting a plated dry wafer back into cassette320. This increases the transporting speed of robot.

FIG. 55 is a schematic view of another embodiment of a plating systemfor plating a conductive film on a semiconductor wafer in accordancewith the present invention. FIG. 55 is similar to the embodiment ofFIGS. 52A-52C except that robot 322 itself can move in the X direction.In this way, the robot may not need the function of rotating around theZ axis.

FIG. 56 is a schematic view of another embodiment of a plating systemfor plating a conductive film on a semiconductor wafer in accordancewith the present invention. The system of FIG. 56 is similar to theembodiment of FIGS. 52A-52C except that the plating baths andcleaning/drying chambers are put in one column. Compared with theembodiment of FIG. 52, the foot print of the system is reduced; however,the wafer throughput is lowered.

FIGS. 57A-57C are schematic views of another embodiment of a platingsystem for plating a conductive film on a semiconductor wafer inaccordance with the present invention. It consists of three columns ofplating baths and cleaning/drying chambers, a linearly movable robot322, a display screen 340, two stacked cassettes, a plumbing box 330,and an electrolyte tank 36. Plating process steps are similar to thosedescribed for the embodiment of FIGS. 52A-52C.

FIGS. 58A-58C are schematic views of a further embodiment of theapparatus for plating a conductive film directly on substrate withbarrier layer or thin seed layer on top in accordance with the presentinvention. The plating bath includes anode rod 1 placed in tube 109, andanode rings 2, and 3 placed between cylindrical walls 107 and 105, 103and 101, respectively. Anode 1, 2, and 3 are powered by power supplies13, 12, and 11, respectively. The charge delivered by each of the powersupplies in the plating process is monitored by charge meters 11A, 12A,and 13A, respectively. Electrolyte 34 is pumped by pump 33 to passfilter 32 and reach inlets of liquid mass flow controller (LMFCs) 21,22, and 23. Then LMFCs 21, 23 and 23 deliver electrolyte at a set flowrate to sub-plating baths containing anodes 3, 2 and 1, respectively.After flowing through a gap between wafer 31 and top of cylindricalwalls, electrolyte is fed back to tank 36 through spaces betweencylindrical wall 100 and 101, 103 and 105, and 107 and 109,respectively. A pressure leak valve 38 is placed between outlet of pumpand electrolyte tank 36 to leak electrolyte back to tank 36 when LMFCs21, 22, 23 are closed. Bath temperature is controlled by heater 42,temperature sensor 40, and heater controller 44. A Wafer 31 chucked bywafer chuck 29 is connected to power supplies 11, 12 and 13. A mechanism30 is used to rotate wafer 31 around z-axis at speed ωz1, and oscillatewafer 31 in the x, y, and z direction. LMFC is an anti-acid or anticorrosion, and contamination free type mass flow controller. Filter 32should filter particles larger than 0.05 or 0.1 μm in order to obtain alow particle added plating process. Pump 33 should be anti-acid oranticorrosion, and contamination free pump. Cylindrical walls 100, 1001,103, 105, 107 and 109 are made of electrically insulating materials. Thematerials are also anti-acid or anti-corrosion, and non-acid dissolving,metal free materials, such as Teflon, CPVC, PVDF, or Polypropylene.

16. Process Steps for Plating a Conductive Film Directly on BarrierLayer or an Ultra-thin Seed Layer.

Step 1: Turn on power supply 11,

Step 2: Turn on LMFC 21 only, so that electrolyte only touches portionof wafer above anode 3. Positive metal ion will be plated onto the areaportion of wafer 31 above anode 3.

Step 3: When the thickness of conductive film reaches the set-value orthickness, go to step 4 with power supply 11 and LMFC 21 on.

Step 4: Repeat steps 1 to 3 for anode 2 (LMFC 22, and power supply 12),go to step 5 with power supplies 11, 12, and LMFCs 21 22 on.

Step 5: Repeat step 4 for anode 1 (LMFC 23 and power supply 13). Whenfilm thickness on whole wafer reaches set-value, turn off all powersupplies and LMFCs at the same time.

During the above plating process, power supplies can be operated at DCmode, or pulse mode, or DC pulse mixed mode. FIG. 59 shows each powersupply on/off sequence during seed layer plating. After completion ofstep 3, the output voltage of power supply 11 can be reduced to a levelsuch that no plating or deplating happens on the portion of wafer aboveanode 3. Also after completion of step 3, and 4, the output voltage ofpower supplies 11, 12 can be reduced to a level such that total chargesdelivered to anode 3, 2, and 1 during time T3, T2, and T1 meets thefollowing requirement:

Q3/(area above anode 3)=

Q2/(area above anode 2)=

Q1/(area above anode 1)=pre-set value

Where Q3 is total charge delivered to anode 3 during whole platingprocess, Q2 total charge delivered to anode 2, and Q1 total chargedelivered to anode 1 during the whole plating process.

Charge monitors 11A, 12A, and 13A are used as in-situ thickness monitor.For instance charge variations caused by fluctuation of any power supplycan be feed back to a computer. The computer can correct the variationeither by adjusting current delivered by the same power supply oradjusting the plating time.

An advantage of above process is that no deplating happens during wholeplating process. Such deplating would cause additional thicknessvariation, and might cause corrosion to the plated film.

FIGS. 60A-60B show another embodiment of apparatus for platingconductive film in accordance with the present invention. The embodimentof FIGS. 60A-60B is similar to that of FIGS. 58A-58B except that outputof each channel is adapted by multi-small nozzles 800. Those nozzleswill enhance the film uniformity.

FIG. 61 shows another embodiment of apparatus for plating conductivefilm in accordance with the present invention. Plating bath 88 isrotated by a mechanism means (not shown) to form a parabolic surface ofelectrolyte. Anode 804 is set inside of bath 88 and connected to powersupply 806. Wafer chuck 29 is driven in x, y, and z movement, and isrotated around the z-axis.

17. Process Steps for Plating Conductive Film Directly on Barrier Layeror Ultra-thin Seed Layer.

Step 1: Deliver electrolyte to bath 800;

Step 2: Rotate bath 800 around z-axis at a speed of ωz2 to form aparabolic surface on top of electrolyte;

Step 3: Turn on power supply 806;

Step 4: Move the chuck down at a certain speed until the whole wafersurface is touched by electrolyte. The rotation angle or tilting angleis in the range of 0 to 180 degrees. The speed of the chuck moving downdetermines initial film thickness distribution. This initial thicknessdistribution affects potential across the wafer during the succeedingplating. Step 5, when the film reaches the pre-set value, turn offelectrolyte pump, power supply, and driving means to drive bath 800.

During the above process, the chuck can be rotated around the z-axis tofurther enhance film uniformity. The rotation direction of the chuck ispreferred to be opposite to that of bath 80.

FIGS. 62 and 63 show another two embodiments of apparatus for platingconductive film in accordance with the present invention. Theembodiments of FIGS. 62 and 63 are similar to that of FIG. 61 exceptthat single anode is replaced by multi-anodes. The height of insulatingwalls located at edge is higher than those located at center of bath.The advantages of these two embodiments provide additional variables tocontrol film uniformity across wafer.

FIGS. 64 and FIG. 65 show another two embodiments of apparatus forplating conductive film in accordance with the present invention. Theembodiments of FIGS. 64 and 65 are similar to these of FIGS. 62 and 63except that the height of insulating walls located from the center tothe edge of the bath are the same.

FIG. 66 shows another embodiment of apparatus for plating conductivefilm in accordance with the present invention. The embodiment of FIG. 66is similar to that of FIG. 61 except that chuck 29 can be rotated aroundthe y axis or the x-axis so that only peripheral part of wafer iscontacted by electrolyte. The rotation angle or tilting angle is in therange of 0 to 180 degrees.

18. Process Steps for Plating Conductive Film Directly on Barrier Layeror Ultra-thin Seed Layer.

Step 1: Deliver electrolyte to bath 800,

Step 2: Rotate chuck 29 around y-axis at an angle θy,

Step 3: Rotate chuck 29 around z-axis at a speed of ωz1,

Step 4: Turn on power supply 806;

Step 5: Move chuck 29 down (z-axis) at a certain speed until the wholewafer surface is contacted by electrolyte. The speed of chuck movingdown determines initial film thickness distribution. This initialthickness distribution affects potential across the wafer during thesucceeding plating.

Step 6: When the film reaches the pre-set value, turn off electrolytepump, power supply, and driving means to drive chuck 29.

During process step 5, after wafer is fully contacted by electrolyte,the wafer chuck can be rotated around the y-axis to make it horizontal.This will enhance the film uniformity.

FIG. 67 and FIG. 68 show another two embodiments of apparatus forplating conductive film in accordance with the present invention. Theembodiments of FIG. 67 and FIG. 68 are similar to that of FIG. 66 exceptthat a single anode is replaced by multi-anodes. The advantage of thesetwo embodiments is that they provide additional variables to controlfilm uniformity across wafer.

FIG. 69 shows another embodiment of apparatus for plating conductivefilm in accordance with the present invention. The embodiment of FIG. 69is a combination of those of FIG. 61 and FIG. 66. The advantage of thisembodiment is to provide additional variable to control position of awafer relative the surface of the electrolyte.

19. Process Steps for Plating Conductive Film Directly on Barrier Layeror Ultra-thin Seed Layer.

Step 1: Deliver electrolyte to bath 800,

Step 2: Rotate chuck 29 around the y-axis at an angle θy,

Step 3: Rotate chuck 29 around the z-axis at a speed of ωz1,

Step 4: Rotate bath 800 around the z-axis at a speed of ωz2 to form aparabolic surface on top of the electrolyte;

Step 5: Turn on power supply 806;

Step 6: Move chuck 29 down (z-axis) at a certain speed until the wholewafer surface is contacted by electrolyte. The speed of the chuck movingdown determines initial film thickness distribution. This initialthickness distribution affects potential across the wafer during thesucceeding plating.

Step 7: When film reached the pre-set value, turn off electrolyte pump,power supply, and driving means to drive bath 800 and chuck 29.

During process step 6, after wafer is fully touched by electrolyte, thewafer chuck 29 can be rotated around y-axis to make it horizontal. Thiswill enhance the film uniformity.

FIGS. 70 and 71 show another two embodiments of apparatus for platingconductive film in accordance with the present invention. Theembodiments of FIGS. 70 and 71 are similar to that of FIG. 69 exceptthat the single anode is replaced by multiple anodes. The advantage ofthese two embodiments is that they provide additional variables tocontrol film uniformity across the wafer.

It should further be apparent to those skilled in the art that variouschanges in form and details of the invention as shown and described maybe made. It is intended that such changes be included within the spiritand scope of the claims appended hereto.

What is claimed is:
 1. An apparatus for plating a film on a substrate,comprising: a substrate holder configured to position the substrate toreceive a plating electrolyte; at least two anodes configured to supplyplating current to the substrate, wherein the at least two anodes areseparated by an insulating wall enclosing each of the at least twoanodes; at least two flow controllers configured to supply the platingelectrolyte; a control system coupled to said at least two anodes andsaid at least two flow controllers to provide electrolyte and platingcurrent to successive portions of the substrate to provide a uniformthickness film on the substrate by successive plating of the film on thesubstrate.
 2. The apparatus of claim 1, wherein the insulating wall ofeach anode is of the same height.
 3. The apparatus of claim 1, whereinthe insulating wall of each anode is of a different height.
 4. Theapparatus of claim 1, wherein the insulating wall of each anodeproximate to a center of the substrate is higher than the insulatingwall of each anode proximate to an edge of said substrate.
 5. Theapparatus of claim 1, wherein a first portion of the insulating wall ofeach anode proximate a center of the substrate being lower than anotherportion of the insulating wall of each anode proximate an edge of saidsubstrate.
 6. The apparatus of claim 1, wherein the at least two flowcontrollers are separate valves for selectively supplying the platingelectrolyte to portions of the substrate adjacent each of the at leasttwo anodes, the apparatus further comprising at least one pump coupledto the separate valves.
 7. The apparatus of claim 6, wherein the atleast one pump comprises two pumps.
 8. The apparatus of claim 6, furthercomprising a pressure leak valve coupled to an outlet of the at leastone pump.
 9. The apparatus of claim 1, wherein the at least one controlsystem is configured to selectively supply plating current to said atleast two anodes.
 10. The apparatus of claim 1, further comprising aninlet and a plurality of nozzles facing said substrate holder.
 11. Theapparatus of claim 1, further comprising at least one electrolyte returnpath.
 12. The apparatus of claim 1, wherein said substrate holder isconfigured to oscillate in a horizontal direction.
 13. The apparatus ofclaim 1, wherein said substrate holder is rotatable around a verticalaxis.
 14. The apparatus of claim 1, further comprising a temperaturecontrol device configured to maintain said electrolyte at a constanttemperature.
 15. The apparatus of claim 1, further comprising a tank anda filter coupled to said at least two flow controllers configured tocirculate electrolyte.
 16. The apparatus of claim 1, wherein saidcontrol system comprises at least two DC power supplies operable inconstant current mode.
 17. The apparatus of claim 1, wherein saidcontrol system comprises at least two DC power supplies operable inconstant voltage mode.
 18. The apparatus of claim 17, wherein the atleast two DC power,supplies are operable in a constant voltage mode anda constant current mode.
 19. The apparatus of claim 1, wherein saidcontrol system comprises at least two pulse power supplies.
 20. Theapparatus of claim 19, the at least two pulse power supplies operable inone of bipolar pulse, modified sine-wave, unipolar pulse, pulse reverse,pulse-on-pulse or duplex pulse mode.
 21. The apparatus of claim 19, saidat least two pulse power supplies operable in a phase shift mode. 22.The apparatus of claim 1, said control system comprising at least onecharge monitor to measure the thickness of film being plated.
 23. Theapparatus of claim 22, wherein said control system controls thethickness of the film being plated on the substrate based on inputreceived from the at least one charge monitor.
 24. The apparatus ofclaim 1, wherein each of said at least two anodes has one of a circular,elliptical or polygonal shape.
 25. The apparatus of claim 24, whereinthe polygonal shape is a triangle, square, rectangle or pentagon. 26.The apparatus of claim 24, wherein each of said at least two anodescomprises at least two sub-anodes positioned to form the one of acircular, elliptical or polygonal shape.
 27. The apparatus of claim 26,wherein the sub-anodes are electrically isolated from each other. 28.The apparatus of claim 1, wherein said control system further includes alogic table configured to recheck continuity of the film.
 29. Theapparatus of claim 1, further comprising a plurality of electrolyte flowchannels; and each of said at least two flow controllers includes avalve and an outlet from one of said plurality of electrolyte flowchannels.
 30. The apparatus of claim 29, wherein each valve and outletis radially positioned relative to a center of the substrate.
 31. Theapparatus of claim 29, wherein each of said at least two flowcontrollers is connected to a pump; and said control system isconfigured to close the valve of one of the flow controllers.
 32. Theapparatus of claim 29, wherein each of said at least two anodes is asingle electrode.
 33. The apparatus of claim 29, wherein said at leasttwo anodes comprises at least two electrically connected electrodes,each of the electrodes being in a different one of the plurality ofelectrolyte flow channels.
 34. The apparatus of claim 1, wherein saidsubstrate holder is movable into the electrolyte to immerse thesubstrate completely into the electrolyte, and said substrate holder ismovable away from the electrolyte.
 35. An apparatus for plating a filmon a substrate, comprising: a substrate holder configured to positionthe substrate to receive a plating electrolyte; at least one anodeconfigured to supply plating current to the substrate; at least one flowcontroller configured to control plating electrolyte received by thesubstrate; at least three cylindrical walls, a first of the cylindricalwalls positioned under a center portion of the substrate located closerto the substrate relative a second one of the cylindrical walls locatedunder a second portion of the substrate peripheral to the centerportion; a drive mechanism coupled to said substrate holder configuredto move said substrate holder to cause one or more portions of thesubstrate to receive the plating electrolyte; and at least one controlsystem coupled to said at least one anode and said at least one flowcontroller to provide electrolyte and plating current to successiveportions of the substrate to provide a uniform thickness film on thesubstrate by successive plating of the film on the substrate.
 36. Anapparatus for plating a film on a substrate, comprising: a substrateholder configured to position the substrate to receive a platingelectrolyte; at least one anode configured to supply plating current tothe substrate; at least one flow controller configured to controlelectrolyte received by the substrate; at least three cylindrical wallsdisplaceable with respect to the substrate, to compensate for a gapbetween the substrate and each of the cylindrical walls to cause one ormore portions of the substrate to receive the electrolyte; at least onecontrol system coupled to said at least one anode and said at least oneflow controller to provide electrolyte and plating current to successiveportions of the substrate to provide a uniform thickness film on thesubstrate by successive plating of the film on the substrate.
 37. Theapparatus of claim 36 in which said at least one anode comprises atleast two anodes.
 38. The apparatus of claim 37, in which said at leastone flow controller additionally comprises at least two valves forcontrolling flow of electrolyte to different portions of the substrate.39. An apparatus for plating a film on a substrate, comprising: asubstrate holder configured to position the substrate above anelectrolyte surface; a first drive mechanism configured to move saidsubstrate holder toward and away from the electrolyte surface to cause aportion of a surface of the substrate to contact the electrolyte; a bathfor the electrolyte; at least one anode mounted in said bath; a seconddrive mechanism coupled to said bath and configured to rotate said bathabout a vertical axis to form a substantially parabolic shape of theelectrolyte surface; and a control system in communication with saidfirst and second drive mechanisms and said at least one anode to provideelectrolyte and plating current to successive portions of the substrateto provide a uniform thickness film on the substrate by successiveplating of the film on of the substrate.
 40. The apparatus of claim 39,further comprising at least one flow controller to supply additionalelectrolyte during plating.
 41. The apparatus of claim 39, wherein saidat least one anode comprises a plurality of anodes.
 42. The apparatus ofclaim 39, further comprising a third drive mechanism coupled to saidsubstrate holder configured to rotate said substrate holder around anaxis perpendicular to the surface of the substrate.
 43. An apparatus forplating a film on a substrate, comprising: a substrate holder configuredto position the substrate above an electrolyte surface; a first drivemechanism configured to move said substrate holder toward and away fromthe electrolyte surface to cause a portion of a surface of the substrateto contact the electrolyte; a second drive mechanism coupled to saidsubstrate holder and configured to rotate said substrate holder aroundan axis perpendicular to the surface of the substrate; a third drivemechanism coupled to said substrate holder and configured to tilt saidsubstrate holder with respect to the electrolyte surface; a bath for theelectrolyte; at least one anode mounted in said bath; and a controlsystem in communication with said first, second and third drivemechanisms and to said at least one anode to provide electrolyte andplating current to successive portions of the substrate to provide auniform thickness film on the substrate by successive plating of thefilm on the substrate.
 44. The apparatus of claim 43, further comprisingat least one flow controller to supply additional electrolyte duringplating.
 45. The apparatus of claim 43, wherein said at least one anodecomprises a plurality of anodes.
 46. The apparatus of claim 43, whereinthe third drive mechanism is configured to tilt the substrate holder ina tilting angle from about 0 to 180 degrees.
 47. The apparatus of claim43, further comprising: a fourth drive mechanism coupled to said bath torotate said bath about a vertical axis to form a substantially parabolicshape of the electrolyte surface.
 48. An apparatus for plating a film ona substrate, comprising: a receptacle having a first section, a secondsection, and a third section, wherein said first section is disposed insaid second section and said second section is disposed in said thirdsection; a substrate holder configured to hold the substrate andposition the substrate within said receptacle; a fluid inlet configuredto deliver an electrolyte into said receptacle; and an anode configuredto apply a current to the electrolyte to plate the film on thesubstrate.
 49. The apparatus of claim 48, wherein said fluid inletcomprises: a first fluid inlet disposed in said first section configuredto deliver the electrolyte into said first section; and a second fluidinlet disposed in said second section configured to deliver theelectrolyte into said second section.
 50. The apparatus of claim 49,further comprising a fluid outlet disposed in said third sectionconfigured to remove the electrolyte from said receptacle.
 51. Theapparatus of claim 48, wherein said fluid inlet comprises: a first fluidinlet disposed in said first section configured to deliver theelectrolyte into said first section; and a second fluid inlet disposedin said third section configured to deliver the electrolyte into saidthird section.
 52. The apparatus of claim 51, further comprising a fluidoutlet disposed in said second section configured to remove theelectrolyte from said receptacle.
 53. The apparatus of claim 48, furthercomprising: a fluid outlet configured to remove the electrolyte fromsaid receptacle; and an electrolyte reservoir configured to hold theelectrolyte, wherein said fluid inlet and said fluid outlet areconnected to said electrolyte reservoir.
 54. The apparatus of claim 53,further comprising at least one mass flow controller connected betweensaid electrolyte reservoir and said fluid inlet.
 55. The apparatus ofclaim 53, further comprising at least one fluid pump connected betweensaid electrolyte reservoir and said fluid inlet.
 56. The apparatus ofclaim 55, wherein said fluid pump is a diaphragm pump.
 57. The apparatusof claim 55, further comprising a pressure leak valve disposed betweenthe outlet of said pump and said electrolyte reservoir.
 58. Theapparatus of claim 53, further comprising: a heater configured to heatthe electrolyte in said electrolyte reservoir; a temperature sensorconfigured to detect the temperature of the electrolyte in saidelectrolyte reservoir; and a heater controller configured to control thetemperature of the electrolyte in said electrolyte reservoir.
 59. Theapparatus of claim 48, further comprising at least one power supplyconnected to the substrate and said anode.
 60. The apparatus of claim59, wherein said power supply is configured to operate in direct current(DC) mode.
 61. The apparatus of claim 59, wherein said power supply isconfigured to operate in pulse modes.
 62. The apparatus of claim 61,wherein said power supply is configured to operate using a bipolarpulse, a modified sine-wave, unipolar pulse, pulse reverse, or duplexpulse.
 63. The apparatus of claim 59 in which said power supply isconfigured to operate in a constant current mode.
 64. The apparatus ofclaim 63 in which said power supply is further configured to operate ina constant voltage mode.
 65. The apparatus of claim 59 in which saidpower supply is configured to operate in a constant voltage mode. 66.The apparatus of claim 48, further comprising a drive mechanismconfigured to rotate the substrate.
 67. The apparatus of claim 48 inwhich said substrate holder is configured to move the substrate relativeto said anode.
 68. The apparatus of claim 63 in which said anode isconfigured to move relative to the substrate.
 69. The apparatus of claim48, wherein said anode further comprises: a first anode disposed in saidfirst section; and a second anode disposed in said second section. 70.The apparatus of claim 48, wherein said anode further comprises: a firstanode disposed in said first section; and a second anode disposed insaid third section.
 71. An apparatus for plating a film on a substrate,comprising: a receptacle having a first section, a second section, and athird section, wherein said first section is disposed in said secondsection and said second section is disposed in said third section; asubstrate holder; a fluid inlet disposed in said receptacle; and ananode disposed in said receptacle.
 72. The apparatus of claim 71,wherein said fluid inlet comprises: a first fluid inlet disposed in saidfirst section; and a second fluid inlet disposed in said second section.73. The apparatus of claim 72, wherein said anode comprises: a firstanode disposed in said first section; and a second anode disposed insaid second section.
 74. The apparatus of claim 71, wherein said fluidinlet comprises: a first fluid inlet disposed in said first section; anda second fluid inlet disposed in said third section.
 75. The apparatusof claim 74, wherein said anode comprises: a first anode disposed insaid first section; and a second anode disposed in said third section.76. The apparatus of claim 71, further comprising: a fluid outletdisposed in said receptacle; and an electrolyte reservoir, wherein saidfluid inlet and said fluid outlet are connected to said electrolytereservoir.
 77. The apparatus of claim 76, wherein said fluid outlet isdisposed in said second section.
 78. The apparatus of claim 76, whereinsaid fluid outlet is disposed in said third section.
 79. An apparatusfor plating a film on a substrate, comprising: a receptacle having: afirst section, a second section, wherein said first section is disposedin said second section, and a third section, wherein said second sectionis disposed in said third section; a fluid inlet disposed in saidreceptacle; and an anode disposed in said receptacle.
 80. The apparatusof claim 79, wherein said anode comprises: a first anode disposed insaid first section; and a second anode disposed in said second section.81. The apparatus of claim 80, wherein said fluid inlet comprises: afirst fluid inlet disposed in said first section; and a second fluidinlet disposed in said second section.
 82. The apparatus of claim 79,wherein said anode comprises: a first anode disposed in said firstsection; and a second anode disposed in said third section.
 83. Theapparatus of claim 82, wherein said fluid inlet comprises: a first fluidinlet disposed in said first section; and a second fluid inlet disposedin said third section.
 84. The apparatus of claim 79, further comprisinga fluid outlet disposed in said receptacle.
 85. The apparatus of claim84, wherein said fluid outlet is disposed in said second section. 86.The apparatus of claim 85, wherein said fluid outlet is disposed in saidthird section.
 87. The apparatus of claim 79, further comprising sectionwalls that divide said first section, said second section, and saidthird section.
 88. The apparatus of claim 87, wherein at least one ofsaid section walls is moveable.
 89. The apparatus of claim 87, whereinat least one of said section walls is divided into at least twosections.
 90. An apparatus for plating a film on a substrate,comprising: a receptacle configured to receive electrolyte and thesubstrate, wherein said receptacle is divided into at least a firstsection, a second section, and a third section, and wherein said firstsection and second section are separated by a first section wall, andsaid second section and third section are separated by a second sectionwall; a first fluid inlet configured to apply electrolyte to a firstportion of the substrate; and a second fluid inlet configured to applyelectrolyte to a section portion of the substrate.
 91. The apparatus ofclaim 90, wherein said first fluid inlet is disposed in said firstsection and said second fluid inlet is disposed in said second section.92. The apparatus of claim 91, further comprising a fluid outletdisposed in said third section.
 93. The apparatus of claim 91, furthercomprising: a first anode disposed in said first section; and a secondanode disposed in said second section.
 94. The apparatus of claim 90,wherein said first fluid inlet is disposed in said first section andsaid second fluid inlet is disposed in said third section.
 95. Theapparatus of claim 94, further comprising a fluid outlet disposed insaid second section.
 96. The apparatus of claim 94, further comprising:a first anode disposed in said first section; and a second anodedisposed in said third section.
 97. The apparatus of claim 90, whereinsaid first section wall and said second section wall have differentheight.
 98. The apparatus of claim 97, wherein said first section wallis taller than said second section wall.
 99. The apparatus of claim 97,wherein said second section wall is taller than said first section wall.100. An apparatus for plating a film on a substrate, comprising: areceptacle divided into at least a first section and a second section bya section wall, wherein said first section is adjacent a first portionof the substrate when the substrate is positioned within saidreceptacle, and wherein said second section is adjacent a second portionof the substrate when the substrate is positioned within saidreceptacle; and at least one fluid inlet configured to supply anelectrolyte into said receptacle; and at least one anode configured toapply a charge to said electrolyte.
 101. The apparatus of claim 100,wherein said at least one fluid inlet is disposed within said firstsection of said receptacle.
 102. The apparatus of claim 100, whereinsaid at least one anode is disposed within said first section of saidreceptacle.
 103. The apparatus of claim 100, wherein the substrate is asemiconductor wafer, and section wall has a circular shape.
 104. Anapparatus for plating a film on a substrate, comprising: a receptaclehaving a first section wall that lies within a second section wall,wherein the tops of said section walls are adjacent the bottom surfaceof the substrate when the substrate is positioned within saidreceptacle, and wherein the section walls have different height; a fluidinlet configured to apply an electrolyte into said receptacle; and ananode configured to apply a charge to said electrolyte.
 105. Theapparatus of claim 104, wherein said first section wall is taller thansaid second section wall.
 106. The apparatus of claim 104, wherein saidsecond section wall is taller than said first section wall.
 107. Theapparatus of claim 104, wherein said section walls are adjustable. 108.The apparatus of claim 104, wherein the receptacle is divided into afirst section, a second section, and a third section by said firstsection wall and said second section wall, and wherein said fluid inletcomprises: a first fluid inlet disposed in said first section configuredto apply said electrolyte to a first portion of the bottom surface ofthe substrate when the substrate is disposed within said receptacle; anda second fluid inlet disposed within said second section configured toapply said electrolyte to a second portion of the bottom surface of thesubstrate when the substrate is disposed within said receptacle. 109.The apparatus of claim 104, wherein the receptacle is divided into afirst section, a second section, and a third section by said firstsection wall and said second section wall, and wherein said fluid inletcomprises: a first fluid inlet disposed in said first section configuredto apply said electrolyte to a first portion of the bottom surface ofthe substrate when the substrate is positioned within said receptacle;and a second fluid inlet disposed in said third section configured toapply said electrolyte to a second portion of the bottom surface of thesubstrate when the substrate is positioned within said receptacle.